This is a summation of the episode 15 of the Landscape, season 2.
With the dead body of Vershaw/Craxle lying before them, the group argues with Kel over his murderous actions. They hope that their knowledge about the Carceri prisoners being technically immortal is true, and that the Myaner will return. They search the hut, and find several maps of the islands. One points them to Town, which seems to be the only regularly populated area on the whole of the prison domain.
In Town, the group gains a lot of attention, and when asking for Linger, inadvertently agree to deal with the Gatewatcher, a devilish black dragon that torments the weaker prisoners. They set out for the Gatewatcher's lair, hoping Linger is imprisoned there.
Well she is. The group catch up with the gold dragon, and JimJam hatches a plan to deal with the Gatewatcher. Everyone hides and plugs their ears, and when the evil dragon shows up, JimJam recites a joke...the Killing Joke.
The Gatewatcher falls dead, and Darvin uses the Gatewatcher's magical bracelets to free Linger from imprisonment. They return to the Conflict II: The Moneyist and begin their getaway from the shattered islands. The Gatewatcher - reanimated by the prisons fell magics, chases them down however, and the group must battle him for their very survival. The fight is long and difficult, but they managed to slay the beast without any fancy murdering jokes, and they collect it's corpse to adorn the ship.
They hit the nearest strand, and rocket through the Astral Sea, arriving in a new domain: a thousand story tower-city made of silver and steel!