Avernus as a Sandbox – Part 2

In Avernus as a Sandbox – Part 1 we talked about how to turn Chapter 3: Avernus of Baldur’s Gate: Descent into Avernus into a sandbox. The goal was to create a structure that offered multiple different ways to go from Fort Knucklebone at the start of the chapter to the Bleeding Citadel, where the characters can find the Sword of Zariel. 

We ended up with this:

In Avernus as a Sandbox – Part 2, we’ll go over over each encounter and location in turn, briefly discussing what we need to change to make the structure work. It’s highly recommended that you read through the encounters in the Baldur’s Gate: Descent into Avernus-campaign book before or while reading this post. Along the way, there will also be references to our DM’s Resources for Baldur’s Gate: Descent into Avernus, but while these resources will certainly be helpful, they are not necessary to make the structure work.

As we go over the various encounters and locations, we’ll also offer suggestions on how to deliver information to the players in an organic way, so that they become aware of the options available to them without feeling like they’re being flooded with information and exposition.

Anyway – let’s get into it!

Fort Knucklebone

In the book, the characters are supposed to undergo a ritual at Fort Knucklebone, venturing into Lulu the Hollyphant’s dreams with Mad Maggie as their guide. At the end of the Dream Quest, Lulu looks into a spyglass, exclaims that she knows where the sword is, and leads the characters to Haruman’s Hill without further explanation.

The logic – or lack-there-of – behind going from Fort Knucklebone to Haruman’s Hill always seemed a bit jarring to me, and since we now need the party to seek out three Intermediaries, who can help them find one of the Fallen Three, we’ll scrap that final dream and alter what the characters experience during the Dream Quest.

Altering the Dream Quest

To open up this part of the story, and give the characters more options – and perhaps options that make more sense than Lulu simply pointing them along without an explanation – we’ll insert Bel, Olanthius and Haruman into the Dream Quest. We do this by replacing Dream 5: Revelation with one or two scenes featuring Zariel, Olanthius, Haruman and Bel:

A terrible scene fills your vision. The angel you saw earlier is surrounded by a throng of fiends, flanked only by two bloodied, human knights wearing the insignia of high-ranking generals. For a moment, it seems like they will be able to hold against the devils surrounding them, but then a mighty pit fiend emerges, wearing a devilish grin and a cruel blade. In one fell swoop, the pit fiend severs the angel’s hand at the wrist, sending her sword flying far away. The vision begins to darken and fade then, just as the legion of devils finally bury the three valiant warriors beneath their unending numbers.

If you want to, you can follow this scene up with another scene showing Zariel’s submission to Asmodeus (or use either of the two, as you see fit):

A huge, dark throne of skulls, blades and bones stands before you. Seated on the throne is a slim, red-skinned devil more than 13 ft. tall, wearing luxurious black and red robes. The angel kneels before the throne, a human paladin kneeling on either side of her. All three are beaten and bloodied, looks of utter defeat on their worn faces. To the right stands an enormous pit fiend wearing a sardonic grin, seemingly presenting the captives. The devil on the throne speaks – the dream muffles the words, rendering them inaudible – and a contract appears in a puff of black smoke to float eerily in front of the captives. The pit fiend seems to roar in protest, but a stern look from the figure on the throne silences the fuming devil. Meanwhile, an angry, resolute look comes over the angel’s grim features, and after only a moment of hesitation, she signs the contract with a bloody finger. As she does, her wings melt away to blackened vestiges, her golden hair withers to bare her pale scalp, and her glowing halo becomes a ring of infernal fire. One paladin bows his head solemnly, before putting his own finger to the contract, immediately sending spasms through his form as it darkens and transforms, turning into something vile and evil. The other paladin roars in grief and anger at the sight of his comrades’ betrayal, and swiftly snatches a dagger from his belt and slices his own throat. His limp form falls to the ground to lie completely still, blood flowing thickly from the deep gash in his neck. Just before the dream fades to darkness, you see the fallen angel leaning over to touch the body, a dark glow spreading from her fingers to cover the paladin’s still form – and the paladin’s eyes reopen, though his gaze remains cold and lifeless.

When the Dream Quest is over, Mad Maggie (or Lulu, if she’s with the party) can help the characters interpret the meaning of what they’ve seen: only those present when Zariel fell knows where to find the Sword of Zariel. Maggie can easily identify Asmodeus (the figure on the throne), but focuses on the other three. She can name Bel, the former Lord of Avernus, as the pit fiend that cut off Zariel’s hand, while Lulu (or Gargauth, if Lulu’s not present) can supply the names of the two generals, Olanthius and Haruman. Unfortunately, neither know where to find these ‘Fallen Three’.

Finding the Fallen Three

To find the ‘Fallen Three’, the party will need to find a very powerful spellcaster. At this point, you can have Mad Maggie name all three ‘Intermediaries’ (Mordenkainen, Red Ruth and Mephistopheles) as NPCs that may be able to locate the ‘Fallen Three’. This gives the party all their options from the start, at the risk of feeling a bit too convenient.

You can also choose to ration the information, having Maggie say something along the lines of: “Hmm… I might know someone who could help you. A distant cousin of mine, Red Ruth, lives out by the Bone Brambles. A darned good diviner that one – but a bit loopy, if you ask me, heh!”

If the party has the Shield of the Fallen Lord, you can have Gargauth chime in: “Red Ruth is hardly the only diviner in Avernus. The archwizard Mordenkainen spends much of his time doing research in Avernus. If anyone can help us find these generals, it would be him. Plus, I’m getting tired of haggling with hags!” Of course, Gargauth has ulterior motives – he hopes that Mordenkainen has the power to release him from his prison. If Gargauth isn’t with the party, you can also have Lulu provide the rumor, or have a character with proficiency in History or Arcana automatically remember that the wizard Mordenkainen often frequents Avernus.

To supply the characters with the third option, you can have them run into some informative NPCs shortly after leaving Fort Knucklebone. In our sample structure, this would be the bounty hunters from the ‘Infernal Bounty’-encounter, but it could also be the Wandering Emporium, Smiler the Defiler, another Warlord, or someone else. These NPCs can drop information about the Mirror of Mephistar if the characters mention that they need to find someone, are looking for information, or just as a random passing comment. Perhaps it was the Mirror of Mephistar that informed the bounty hunters where to find the party – “so if you need to find someone, well, that would be my best bet” – or any mention of a powerful spellcaster will make Mahadi, Smiler or a Warlord tell the party that “there’s no spellcaster more powerful than Mephistopheles – so that’s what I would recommend!”

The Intermediaries

Below, we’ll quickly go over how to alter the three encounter locations that constitute our ‘Intermediaries’: Mordenkainen at the Tower of Urm, Red Ruth at the Bone Brambles and Rigorath at the Mirror of Mephistar.

Mordenkainen (Tower of Urm)

You can run the encounter with Mordenkainen exactly as it is described in the book, or the more elaborate version from our DM’s resources for Baldur’s Gate: Descent into Avernus, altering only the information Mordenkainen gives the party. Instead of sending the characters along to the Obelisk, Mordenkainen asserts that he can easily find any of the ‘Fallen Three’ (the location of the Bleeding Citadel itself, however, is hidden even from him). Before the wizard will tell the party anything, however, he wants them to retrieve a pint of blood from a balor, a pit fiend, or a creature even more powerful – an ingredient he often needs for his arcane experiments. Mordenkainen has no idea where to find such a creature, and won’t waste time helping the party find out, instead sending them on their way to find out on their own.

Red Ruth at the Bone Brambles

Once again, you can run this encounter pretty much as it is described in the book. After making their way through the maze, Ruth asks the party to arrange and pay for her pampering session at the Infernal Rapture in the Wandering Emporium, and watch over her grove while she’s away. When that whole deal has been resolved, Ruth tells the party that she’ll help them with the ritual, but that it will require blood from a creature at least as powerful as a balor or a pit fiend. Her only suggestions are Zariel and Bel, both of which are quite unlikely, so once again the characters are on their own. 

Mirror of Mephistar

At the mirror of Mephistar, Rigorath informs the party that Mephistopheles can help them ascertain the location of any of the ‘Fallen Three’, but that he requires a service in return. Like Mordenkainen, Mephistopheles is always in need of powerful blood for his arcane experiments, although his true motivation for offering this quest is more nefarious. Mephistopheles knows it will be hard for the party to get the blood without somehow causing chaos in Avernus – chaos that will harm Zariel and, thus, benefit Mephistopheles. Once again, the adventurers are given no directions, but told to find out on their own.

Where to now?

This is where we enter true sandbox-territory. The characters know they have to find blood from a powerful creature – but where can they learn more about one of those?

Literally anywhere you choose. You can have any NPC they come across have information about Arkhan, Uldrak, Ubbalux or Shummrath. They can learn about them from Gargauth, Lulu, Mad Maggie, the yugoloths outside Mordenkainen’s Tower, a random imp they meet on the plains, or the other ‘Intermediaries’, if they seek them out.

However, this is also the perfect point to introduce the Wandering Emporium, which we’ll describe in more detail below.

The Wandering Emporium

The Wandering Emporium is a fun location, which also works really well as a hub for information. You’ll probably want to make sure that the characters find it early, so they always have somewhere to return to when they need more information, or are unsure about what to do. So, how do we get them there?

Getting to the Wandering Emporium

Of course, the Wandering Emporium can just show up right after the party has visited an Intermediary. But, the party might also seek it out on their own (and this can feel more rewarding) – below we’ll go over some ways you can make that happen:

  • The pair of nycaloths from outside the Tower of Urm ambush the characters after their visit at the tower, and a surviving fiend surrenders and offers to aid the characters, potentially leading them to the Wandering Emporium.
  • The characters ask Gargauth where they can find blood from a powerful creature – and though he doesn’t know, he can suggest that Mahadi from the Wandering Emporium might.
  • The party asks Lulu, who doesn’t know, but vaguely remembers a caravan filled with all manners of exotic and powerful creatures: the Wandering Emporium.
  • The party goes to one of the other ‘Intermediaries’ in search of a powerful creature. In all three cases, the party learns something from the NPC, but has to go to the Wandering Emporium first – where they can learn even more, if they think to ask:
    • To Red Ruth, who now can’t help them find the ‘Fallen Three’, but can tell the party about Ubbalux – a balor in disguise – if they secure her a spa treatment at the Infernal Rapture at the Wandering Emporium.
    • To Mordenkainen, who can inform the party about Uldrak, if they first pick up some demon ichor for him from Ichor’s Aweigh at the Wandering Emporium.
    • To the Mirror of Mephistar, where Rigorath can tell the party about Arkhan and the blood of Tiamat, if the characters fetch some yugoloth larvae from Zneth’s Larvae Farm at the Wandering Emporium.

If you want to make finding the Wandering Emporium a bit more convenient and less random, you can have NPCs – or Mahadi himself, after their first visit – give the characters a Wandering Coin. If thrown on the ground, this dented, rust-colored coin, showing Mahadi’s grinning face on one side and a tiger’s paw on the other, begins rolling along on its side 10 feet in front of whoever threw it, unerringly leading the way to wherever the Wandering Emporium is at that moment.

The Emporium as an Information Hub

So, how do we give the party information at the Wandering Emporium?

We can assume that the party will first ask Mahadi, who can – at your discretion – know as much or as little as you’d like. I have found that it works best if Mahadi doesn’t know much himself, but freely names the various NPCs in the emporium, many of which will be able to help. This allows the players more agency in finding out information, instead of just getting everything from one source.

The following NPCs can help the party find a powerful creature’s blood:

  • Rassh, Skidds & Slagg at the Firesnake Forge know that Bel (their former employer) has imprisoned a pit fiend named Shummrath in a crevice near the River Styx. They can also sell the party Shattersticks to help free Shummrath.
  • Burney the Barber knows that Arkhan carries Tiamat’s blood in a vial around his neck, and freely points the party to Arkhan’s Tower in the hopes that the adventurers will kill Arkhan, or at least hinder Arkhan’s plans to free Tiamat.
  • Elliach at Ichor’s Aweigh knows that Ubbalux – seemingly a wizard imprisoned by an obelisk – is in fact a balor, and can point the party to the Obelisk.
  • Fhet’ahla knows about Uldrak – his imps have told him about a spined devil who insists that it is in fact an empyrean, hanging out near a gargantuan sword and helmet on the plains of Avernus.

The point here isn’t that the characters need to discover all four options, but that it should be relatively easy for them to do so, if they put in just a little effort. They might only learn about one, and just go for that option – and as long as they know that more options likely would have been available, if they had asked around more, then that’s perfectly fine. Remember also, it’s always up to you which of the options you want to emphasize or withhold, if there’s any options you particularly like or dislike.

Blood Pay

The next leg of the characters’ journey leads them to either Arkhan (Arkhan’s Tower), Uldrak (Uldrak’s Grave), Ubbalux (Obelisk), or Shummrath (Pit of Shummrath), where they can recover a pint of blood for the ‘Intermediary’ of their choice. Below we’ll go over how to make each of these encounters/locations fit the new structure.

Arkhan’s Tower & Monument to Tiamat

The characters’ arrival at Arkhan’s Tower can be handled exactly as described in the book, except that the characters won’t have an Orb of Dragonkind to trade. After being led to the Monument to Tiamat by Krull, the characters will have to – as in the book – trade or fight with Arkhan to obtain Tiamat’s Blood.

Arkhan offers his deal – the sacrifice of a good-aligned creature for a vial of the dragon queen’s blood. Once again, Lulu is an ideal candidate, but characters who ask around with NPCs they’ve already met – one of the ‘Intermediaries’, someone at the Wandering Emporium, etc. – can also learn about Mooncolor at the Demon Zapper or Krikendolt at the Spawning Trees, both of which meet the criteria. Or, as adventurers are wont to do, they may go toe-to-toe with Arkhan and his followers in an epic battle instead, and hopefully live to tell the tale (we have some notes about handling that battle in our DM’s resources for Chapter 3: Avernus).

Uldrak’s Grave

Uldrak is an empyrean, who ventured into Avernus to slay Tiamat, but was defeated and transformed into a lowly spined devil by the dragon queen – a form he has now held for millennia.

In the book, Uldrak must spill the blood of Tiamat on the ground of Avernus to break the curse – and tells the party as much, while showing them the Orb of Dragonkind that sits in the pommel of his giant sword, in the hope that they will trade the orb for the vial of Tiamat’s blood Arkhan the Cruel carries around his neck.

Because the party is already out for powerful blood, we don’t want Tiamat’s blood to be the way to break Uldrak’s curse. Instead, Uldrak must slay a dragon for the curse to be broken – a solution chosen by Tiamat to cruelly mock the empyrean’s new, puny form. However, with the party’s help, slaying a dragon might not be all that impossible. In fact, Uldrak even knows where to find a dragon: there’s several of them by Arkhan’s Tower, a five-spired monstrosity not far from Uldrak’s Grave.

If the characters go to Arkhan’s Tower intending to slay a dragon, it’s likely they’ll get into a fight with Krull and the dragons at the tower. If they face everything at once, this fight is extremely dangerous, so you may want to split things up a bit, having the party face Krull, the dragon Obatala and his ghouls, or Krull and the four young/wyrmling dragons residing in the tower. To break the curse, Uldrak simply has to participate in the killing of the dragon. If the transformed empyrean dies in the process – well, the party will have to go somewhere else for the blood they’re after.


At the obelisk, the party finds a trapped demon disguised as a wizard, who first makes them perform an arcane ritual before eventually revealing its true identity and sending the party toward Mephistopheles at the Mirror of Mephistar.

You can run this encounter pretty much as it is, changing only two things: Ubbalux is a balor, not a barlgura, and it doesn’t point them to Mephistopheles at the end of the encounter.

Ubbalux is a balor (instead of a barlgura) both because it makes more sense, but also because the party needs to find a powerful creature, and not just any old demon. And because the party might have already been by Mephistopheles, we don’t want the archfiend to be the solution to Ubbalux’ predicament.

Instead, Bel has made the way to free the balor so difficult, it might as well be impossible: to break the obelisk’s hold on Ubbalux, another creature has to willingly and without coercion take the demon’s place in the prison – while being fully aware that this means being trapped for eternity (or until another creature willingly takes their place).

Since self-sacrifice and selflessness are some of the rarest commodities in Avernus, Ubbalux has all but given up on being freed this way. However, if the party asks around (likely informants could be Ellioch at Ichor’s Aweigh, Smiler the Defiler, or other NPCs who travel a lot or deals with demons), they can eventually learn about a bearded devil out by the Spawning Trees, who’s recently become very soft-hearted. Or, you can also just have the party find the Spawning Trees by pure chance and realize the opportunity for themselves.

Regardless of how they arrive at the Spawning Trees, they can here save Krikendolt from his bullying comrades, and easily convince the devil to give his own freedom up to free Ubbalux (“it’s just sooo sad that he has been imprisoned for so long, unable to go home. Of course, I’ll take his place!”). If you want to top off the ordeal with an encounter, you can have a weakened Ubbalux – a balor with four levels of exhaustion – immediately take his pent-up rage out on the party, instead of upholding his end of the bargain!

If the characters can’t convince anyone to take the balor’s place, or fail to extract the blood from the freed Ubbalux, they will have the other options waiting for them.

Shummrath’s Pit

This encounter can run just like in the book (with the salamanders in the Wandering Emporium providing the Shattersticks instead of Mephistopheles) up until the point where the river’s flow is dammed. After damming the River Styx, the party will have to wait around for about 24 hours, as Shummrath reforms enough for them to harvest its blood. To add an encounter at the end, you can have the weakened, but now sentient, pit fiend put up a fight. Even with four levels of exhaustion (disadvantage on everything, speed and hit points halved), the pit fiend should still present a decent challenge for the party.

Paying with Blood

When the characters return with a flask of blood for their intermediary of choice, they can finally learn the location of one of the ‘Fallen Three’:

  • Mordenkainen’s simulacrum closes his eyes for a brief second, accessing the memories of his main form, before swiftly (and impatiently) relaying the location of the Fallen Three.
  • Red Ruth brews a stinking concoction with the blood, inhaling the fumes as she sends her consciousness flying across the vast plains of Avernus to seek out the Fallen Three.
  • Rigorath, Mephistopheles’ cambion, disappears into the portal for a few hours, and reappears unceremoniously to give the party their answer.

Now, it’s up to you whether Red Ruth, Mordenkainen or Mephistopheles can provide the party will the locations of all three fallen NPCs, or only one of them – but no matter what, it should be the characters themselves that get to decide which one they will seek out.

(A quick note here – if the characters want to seek out Bel, you may want to have the Intermediary draft up a letter of introduction for the party, so you can run the encounter at Bel’s Forge by the book!)

Smiler the Defiler

Somewhere during ‘Blood Pay’ or soon after, our structure calls for another travel encounter. Here we have chosen Smiler the Defiler, but once again, you can use any travel encounter you’d like. The purpose of this encounter is to supply the party with additional guidance and information – if they need it – but also to make Avernus feel alive and exciting by breaking up the monotony of travel.

When using Smiler the Defiler, we do using our own published adventure Bitter Rivals, which has Smiler beseeching the party to help him get vengeance on Bitter Breath and his hobgoblin marauders. This encounter gives the party a nice, hardy combat challenge and an opportunity to flex their infernal war machines. You don’t have to use that adventure, of course, there’s a hundred different ways you can have Smiler show up to interact with the party.

As mentioned above, Smiler can also serve as a conduit for information if the characters are unsure about where to go next during their search for a powerful creature’s blood. A traveling soul is likely to know much about Avernus – where to find a fiend dumb enough to give themselves up to release Ubbalux, how to find an innocent creature to sacrifice to Arkhan, where to locate a dragon to end Uldrak’s curse, or where to find explosives potent enough to dam the River Styx.

Fallen Three

In the final part of Chapter 3, the party heads toward one of the Fallen Three: Bel, Olanthius, or Haruman to finally discover the location of the Bleeding Citadel.

Bel’s Forge

You can run the encounter with Bel exactly as it is in the book, only cutting out the Sibriex – or keeping it in, if you like it, it won’t matter if the party never seeks out Haruman – and perhaps adding the Arches of Ulloch as the key to finding the Bleeding Citadel, if you want to run that encounter as well (more on that below). Everything else remains the same: the characters are accosted by devils outside of the forge and attacked by fire giants within, before they can finally strike a telepathic deal with Bel to find the adamantine rods in the Wrecked Flying Fortress in return for the location of the Bleeding Citadel.

Haruman’s Hill

The encounter at Haruman’s Hill can also be run much as it is in the book, and you can even include the Hellwasp Nest if you want to beef up the fight a bit. Regardless of the circumstances, Haruman fights to the bitter end, not allowing himself to be taken alive.

When Haruman is destroyed, his fiendish form shifts back into that of a human paladin – greyed, bloodied and broken. If the characters try to speak with the corpse, all they get is dead silence – no soul resides within Haruman’s broken form.

At this point, you can have Jander Sunstar chime in, saying that he knows that there are ways to extract memories from even a soulless body. Perhaps he even knows of a creature wielding such powers – a sibriex – which he’s seen travelling through Avernus. It’s up to you whether Jander also knows where the sibriex is, or if the characters will have to find out through other means (causing them to revisit other NPCs, or giving you another opportunity to put in a travel encounter).

Alternatively, you can leave the characters with no information and see what they do – do they seek out another of the Fallen Three, or take the body with them and try to find some way to reach its memories (perhaps Red Ruth, Mordenkainen or Mephistopheles can extract information from the corpse in return for more blood, giving you a chance to run more of the book’s content!)

If the characters do seek out the sibriex, this encounter runs pretty much as in the book, except it is Haruman’s memories and not the location of the adamantine rods, that the party is after. The sibriex can, by devouring the body of Haruman, relay the location of the Bleeding Citadel (or that the way is through the Arches of Ulloch!) to the characters but will only do so if they free it first.

Crypt of the Hellriders

You can run this location exactly as it is in the book, except switching around the Arches of Ulloch and the freeing of Kostchtchie, if you want to use the Arches as the only way to reach the Bleeding Citadel (as described below). The encounter with Olanthius otherwise requires no changes.

Arches of Ulloch

I personally find that the Arches of Ulloch is a pretty dull encounter, as it is used in the campaign book. A teleportation portal serves little purpose in a place where distance and time is already abstract – unless, of course, we decide that the Arches of Ulloch is the only way to reach the Bleeding Citadel.

This makes sense if Asmodeus has hidden away the Bleeding Citadel with powerful magic in an attempt to ensure that no creature – Zariel least of all – can find the sword. The only way to reach it from Avernus itself (the demons scouring through the citadel have arrived through their own magical means) is through the Arches of Ulloch.

In our DM’s resources for Chapter 3: Avernus we’ve written up an extensive encounter for the Arches of Ulloch, which has the place guarded by an infernal androsphinx, but you can choose any guardian you like, such as a young red shadow dragon, a battalion of yugoloths, or something else you find fitting. The point of the Arches of Ulloch is to challenge the party a bit before they move on from chapter 3, and to give a logical explanation for why the Bleeding Citadel is so damned hard to find!

Coming Up Next

Part 1 and 2 of this series should give you more-or-less what you need to run Avernus as a sandbox. You may still have some questions or concerns, so in the 3rd and final part of this series, we’ll offer general advice, troubleshooting and final thoughts that should help you turn Avernus into a fun and entertaining sandbox for your players.

Until next time – have fun in Hell!

J. A. Valeur

7 thoughts on “Avernus as a Sandbox – Part 2”

  1. Pingback: Avernus as a Sandbox – Part 1 – Eventyr Games

  2. Pingback: Avernus as a Sandbox – Part 3 – Eventyr Games

  3. Question. Red Ruth will help the party with the ‘ritual’. Is that a ritual of divination? using the powerful blood to perform ritual that informs the party where one of Fallen Three are located?


    1. I can see that I could have made that bit a lot clearer – sorry! Yes, a ritual of divination that can ascertain the location of one of the Fallen Three, you’re exactly right 🙂

      1. In order to find Bel, Red Ruth needs the blood of a powerful devil. Her suggestion is to get the blood of Bel. The guy they need her help finding.

        Is this why Mad Maggie calls her loopy?

  4. Sorry, but can you explain the logic of the altered dream quest in a little more detail? You have Zariel, Olanthius, Haruman, Bel, and an army of devils. Bel cuts off the hand with the sword. It flies off into the distance…but then when do the “fallen three” see what happens to it? And why doesn’t this army of devils see it too? And where is Lulu during all this, as this is ostensibly her memory?

    I really like the mechanics of how you’ve structured this chapter, but these are questions my players will probably ask.

  5. Hey, I have a question about Mooncolor.
    How are they supposed to get the unicorn to Arkhan? Like, Mooncolor would not like to be sacrificed, and I think he would just teleport away when he can. I dont think it would be easy to find him, he even has “pass without trace”, making the search for the unicorn almost impossible to succed.

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