Artefact summaries may contain spoilers
Scene summaries may contain spoilers
Morning breaks in the grove, and all looks hopeless: the Roman Legions are preparing to march in the distance, and revenants swarm outside the grove. You need to stop the Legion from marching, or else Aeneas will turn the Picts into revenants to march against them. Maeve reveals that Sam's shamanic mark is of the otherlands, meaning he can open portals to walk through the afterlife and emerge wherever he wishes. Together, they open a portal, and, in cloaks that will stop the afterlife monsters from seeing you, you all run through.
You all arrive in not the afterlife of the Pictish, but in the Tartarus, where the shades of the unrighteous Roman dead are punished. Maeve realises that some of those being tortured are Pictish, and therefore Aeneas stole not only their lives, but their afterlives. Maeve senses that the second portal has opened near water and heat, which Petronius identifies as Phlegethon, the flaming river. Maeve says she'll try to find it using the minds of the ravens here, but for now, you all run towards the castle.
You get through the screeching gates, and find the dead hydra beyond. There are bite marks all over it, and you hear a terrible roar. Petronius isn't so sure that these cloaks will protect you and wants to tell you all something, but the roaring creature draws nearer, so you must run towards the abyss.
The abyss is deep, said to be a nine-day fall, and the bridge appears only if you try to step across it and have lived a good life. Petronius thinks that the bridge won't work for him, but luckily you all make it on and begin to run.
The bridge begins to crumble behind you before you're even halfway across and Petronius reveals it is his fault. Aeneas' plan was to get Sam to kidnap him, so he could be led to the Pictish, and Petronius agreed to help so he could get his 40 acres in retirement. Petronius insists that you all let him fall into the abyss, but you catch him before he can. You must run fast to stop yourself falling in, too.
The bridge collapses just as you manage to get to the other side. Petronius reveals it was he who forged the letter from the Emperor, and used the power of suggestion to get Sam to meet with Maeve and to kidnap Aeneas. Maeve is angry, until she notices one of the shades strapped to a burning wheel is her wife, Orla. In trying to rescue her, her cloak catches on fire and turns to ash. The roaring begins anew, and Petronius recognises the creature as Cerberus, the three-headed hound of hell. It leaps across the abyss, and Sam insists they'll come back for Orla but now they need to find the portal.
You reach the flaming river Phlegethon, but Cerberus has you cornered. Petronius decides to sacrifice himself, by giving Maeve his cloak and making her promise to live so she can save Orla later. Cerberus follows Petronius, and Maeve realises the portal is on the other side of the river. Just as Sam loses hope, the flames part and Charon the boatman appears. You all get into the boat.