Recovering from their encounter with the ‘Murder Circus’, the crew dedicate themselves to their plan to recover Jawbone Jack’s treasure map from the sunken wreck of The Guiding Star. To do this, they need a diving bell, and Erik knows an old crewmate who now works for the seabed-exploring Society of Lobstermen. The crew visit the Society’s remarkably secure, remarkably well-appointed compound on the Docks, and Erik negotiates to hire a diving bell – with a brief distraction as Estrella breaks into a large wooden lobster-like submersible and almost goes on a mechanical rampage through the Lobstermen’s headquarters.
With the bell installed, the crew take The Travelling Lady out right away, sailing through the night rather than risk further incidents. In their dreams, they recall the terrible battle with Jawbone Jack and his ghoul pirates, the battle in which Captain Rudder died and the Star sank. It’s a sad, traumatising series of memories – and a disturbing one, as Estrella suddenly remembers seeing Captain Rudder being stabbed in the back while fighting Jawbone Jack. Did one of the crew betray their captain?
By midday, the Lady reaches the site of the battle, in an area where schools of red algae leave the waters permanently red as blood. Jobu and Pete swim down in the diving bell to find the wreck, while the others keep watch on the ship. Roger sees a ship on the horizon, and sounds the alarm – but there are nearer dangers, as the ship is attacked by merfolk and a giant albino moray eel, the same creatures that have been sinking ships in Freeport! As the crew battle the attackers above, Jobu fights off a monstrous jellyfish in the wreck of the Star, and Pete discovers the map in the skeletal hand of Captain Rudder’s corpse – a corpse that grabs him as he attempts to take it!
In a frantic fight, Farn kills the merfolk leader and savagely tears into the moray with his ghoulish claws, and Roger witnesses the cabin boy’s inhuman power as he dispatches the other attackers. Jobu rips apart the jellyfish, and Rudder’s corpse releases Pete after whispering in his ear, ‘The monkey murdered me.’
The crew reunite on the ship, crack the case and examine the map – etched on cured human skin, it shows some kind of ruins deep within nearby Ape Island. As they prepare to weigh anchor, Roger checks the horizon to see that the other ship is also headed for Ape Island – and it flies the flag of the Murder Circus!