The group chase after Serra, who has transformed into her snake form and slithered off through the swamp in search of poachers. Breaking through the foliage into a clearing, she finds a half-submerged steamboat, laying at an acute angle in the boggy surface. She follows the flickering light coming from the open cargo bay doors in the ship’s deck. The rest of the team rock up after she’s already out of sight, and are spooked by what they find. Fi doesn’t like the creepy vibes given off by the forgotten ghost ship, and Roe’s fear of water is already being pushed to its limit with her being knee-high in the swamp. The ranger opts to run back to the frogs, whom she left Baxter to guard, while Rurron and Lissie — the former more than ready to beat some poachers up, the latter itching for adventure — convince the immolator to face her fears and climb aboard.
In the cargo hold, Serra sneaks down the stairs and conceals herself behind some barrels. From her vantage point, she spies two elves hoarding large jars. However, in the dim light provided by the gas lamps around the hold, she struggles to make out how many poachers there are, and what exactly it is they’re making off with. Nonetheless, she strikes out against the closest of the elves. Still slightly drunk on snake-god power, she eschews her usual melee attacks and sinks her teeth right into the poacher’s shin, drawing blood and a loud cry from her victim, followed by a club to the head. The yelp attracts the attention of the other elf across the room who, spooked by the noise in the dark, begins to cautiously approach his injured chum.
Back at the edge of the swamp, Roe attempts to get some information out of the frog-ilk who “greeted” the group upon their arrival and put Serra onto the trail of the poachers. They have no reaction when she brings up the university the gang are looking for, profess to have no knowledge of what a dog is (much to Baxter’s chagrin), and are suspiciously cagey when it comes to the steamboat. The older of the frogs introduces himself as Bob, and the younger as Gary. The former professes not to be a big fan of humans, implying that its usually such people who come to pillage whatever goods it is the boat holds.
On the main deck of the boat Fi, Lissie and Rurron cautiously make their way along the side closest to the ground, unable to scale the sheer approach to the other side. They find a couple of doors, and a collection of barrels huddled beneath a pair of portholes. Fi goes to peer into one of the barrels, only for her foot to break through one of the old, rotting floorboards beneath her. She leaps back, frightened but unharmed. Rurron pats her on the shoulder, then leans her sizable frame across the hole and finds that the barrels are empty, but for a load of mould. Fi is, understandably, disgusted by this discovery.
Down below deck, Serra once again strikes against the first elf. When the second approaches and notches an arrow in his bow, Serra dodges the attack by transforming into a swarm of mosquitoes — through which the missile passes harmlessly — and then back into a snake. The poachers were already pretty terrified when they assumed this was some kind of giant wild snake who had clambered in from the swamp; now they seem to be facing some kind of shapeshifter, they appear even more freaked out. Taking advantage of their shock, the druid returns to her regular form and hotfoots it back up the steps, closing the cargo bay doors behind her and dragging a couple of barrels on top of it to block the poachers in.
Up on the deck of the boat, Fi cautiously attempts to open the left-hand door, finding it locked. Rurron makes short work of it, and Fi picks up one of the broken planks of the now-demolished door to use as a torch. Stepping over the threshold, the flames reveal a room covered in spores and fungi, the low iridescent glow they give off illuminating the darkness along with Fi’s burning brand. It would be beautiful, if you were into that sort of thing, but the assembled group are just sort of grossed out by the smell. They back out and go to investigate the door on the other side, which nearly collapses when Fi opens it. This time, gesturing inside with her torch reveals a room absolutely covered in bones.
Roe continues to struggle with the frogs, who refuse to give any details about the boat while asserting how important it is to them. They don’t seem to be great at conversation anyway. Bob asks if her friends are trustworthy, to which Roe replies “Sure, when they’re not setting things on fire!” The off-handed comment is enough to put the fear of (fantasy) god into the two frog-ilk, but Bob stops Gary from explaining why exactly they’re so concerned by this information. Pushed to her limit — worried that the rest of the group may be in trouble, and these frogs aren’t helping; also, just kinda sick of this pair — Roe draws her sword and tells Gary she will rob all the swamp’s treasure herself if he doesn’t explain the deal with the boat.
He puts his hands up, while Bob picks up his spear and trains it on the ranger, creating a classic (fantasy) Mexican standoff! Roe loses her bottle a little, not actually being prepared to murder some innocent froggos, and says she just wants to keep everyone safe. Sufficiently convinced of her pure intentions, Gary is allowed to explain that the spores which grow in the very, very old boat are the cornerstone of their culture: they ferment drinks with it, the mould is used as a recreational drug, it produces energy, they cultivate fungus-based foodstuffs from it. Poachers frequently come to nick it, and they’re worried about all the spores being taken away and their way of life disappearing with it. He also explains that the fungus is highly flammable, hence their panic at Roe’s gag.
Having blocked the cargo hold doors, Serra follows the voices of her friends and rejoins Rurron, Lissie and Fi. No longer connected directly to the swamp (because her feet are firmly planted on the boat!), she has gotten over her swamp-god mania somewhat, and slumps against the wall in a daze. The three fill her in on what they’ve found. Roe follows up behind them, getting over her fear of water long enough to climb up onto the boat and warn everyone with the information the frogs gave her. Baxter is immediately restless, smelling the bones in the right-hand room, and Fi coaxes him in, whilst expressing scepticism about how important the mould is. She’s still mostly grossed out by it. Serra, apparently no stranger to spores, pipes up that “mould is alive.”
From the room full of bones, the group hear Baxter’s joyful revery interrupted by a gruff voice reprimanding him. They all freeze. Roe advances slowly towards the room, studying the bones — she used to hang out in her dad’s butcher’s shop as a kid — and discovering that not only do they appear to come from a variety of different animals, some of them are positively ancient while some look like they’ve been there a week. Roe calls out to Baxter, lost in the darkness, and he rejoins her, barking that there was a man who told him off. The ranger is incredulous, but her dog is insistent.
Roe asks Fi, still holding her torch, to illuminate the room. As the immolator steps forward, Roe remembers what the frogs said about the dangerous flammability of the boat, and pulls her back across the threshold. The pair bicker, while behind them Serra silently picks up a lantern from the bits of bric-a-brac concealed among the bones, magically illuminating it without the need for fire. She steps into the doorway and, lighting the room up, reveals a man sat upright against the far wall, looking a little worse for wear. He appears to be very old, and he has a large crop of fungi growing out of the side of his face, his chest, and right leg, which are almost fusing him to the wall and ground. He repeats his previous complaint, that Baxter was chewing on his leg. Serra asks what the man’s doing here, and he counters that he could ask her the same thing.
Through a peculiar line of questioning, the group ascertains that the man doesn’t remember how long he has been here, although he once was a member of the boat’s crew; in fact, at this point, he more or less is the ship; he has become one with the mould, which was introduced to the swamp by the boat, and it exists as a sort of hive-mind, meaning he has been able to “explore” the whole swamp despite his apparent immobility; he confirms that poachers are, sadly, common, and that by removing the spores from the swamp and mistreating it he kills it. Serra, still feeling a little #blessed, decides to try out one of her new powers on the mould-man. She places a hand on his, and a glowing rush of water appears out of nowhere, flowing over first his arm and then the rest of his body. Once it passes, the mould appears to no longer be securing him in place. He cautiously moves his head forward from the wall, and then gets to his feet, the fungi hanging down from his back and arm, a trail of spores following in his wake.
He asks Serra what she did. She explains that she sanctified him, although she doesn’t fully understand how. Roe is impressed, but also finds the whole scene pretty weird. Fi is generally just gobsmacked by the whole freaky situation. Serra asks his name, but he doesn’t remember having one; she suggests Ustilago, or Osti for short. He thanks her, and asks if she might do him one more favour: dealing with the poachers below deck.
The group return to the cargo hold doors, pulling the barrels off and allowing the elves to burst forth onto the deck. Roe immediately loosens an arrow at the already-injured elf, before Serra and Fi (the latter of whom is still trying to avoid using her control over flame) roll the barrels at the poachers and crush them underneath. While they’re prone on the stairway, Rurron leaps atop the bow-wielding elf and knocks them out with one punch to the head, and Lissie rushes in to make short work of the other with their dagger, surprised by their own strength; they give the unconscious elf a celebratory punt, but stubs their toe. With the poachers incapacitated but alive, the group plan to get to the bottom of who’s behind this swamp-pillaging.