They arrive in Lusterqal only to be confronted by Sartrand, another Collossum, apparently rogue and no longer serving the Elders that rule the Collossum and all R’loth. Layanna believes him to be a Muugist. The reason the R’loth had to escape their own set of dimensions was because of the awful beings known as the Muug, mighty god-things dredged up from a nightmarish abyss. Some of the R’loth worship the Muug, and it is feared that some of these Muugists managed to infiltrate those who fled their home set of dimensions to this world.

Whoever Sartrand serves, he gives Layanna a way to summon him and his allies, presumably other Muugists, if they need help. He wants the Device for himself, though he doesn’t say why.

Avery and the others arrive at the secret headquarters of the Black Sect to discover, as they feared, that the renegade gods are diseased and dying. The Device isn’t finished and activating it will be arduous, though Avery isn’t told how, not then. He does learn that the Great Temple of the Collossum is summoning all Collossum to it for an urgent meeting about how to end the threat of the Black Sect. The only way to gain access to this meeting is for some infected person to infiltrate the Great Temple and listen in on the gathering.

Avery takes this task upon himself. He eats diseased seafood and becomes infected by the Atomic Sea. His only mutation is some subtle striations across his torso, neck and lower face. He enters the Temple, overhears the plans of the Collossum (as delivered by Uthua, who has become a near-Elder), and escapes, but on the way out he bumps into none other than Sheridan … and Ani. True to her word, the admiral had brought the girl back to life and now she is Ani’s guardian. Seeing Avery, Sheridan sends the girl away.

Furious, Avery kidnaps Sheridan and escapes with her, meaning to get Sheridan to help him release Ani from Octunggen custody. The others are upset when he takes Sheridan into the heart of the Black Sect camp, where she is locked away. Avery tells them what he’s learned, they compensate, and the Device is completed. Now all that’s left is to activate it. Finally Avery learns what this means.

The Device is to be taken by underground train back toward the Atomic Sea, for only by the powerful, otherworldly energies of its waters can the Device be activated and Octung defeated. The Black Sect is expecting pursuit, as Octung desperately wants the Device for themselves. If the Octunggen can reverse its functions, they can make their otherworldly weapons even more powerful.

Sheridan escapes and signals the Octunggen authorities. Uthua himself leads the attack on the Black Sect, who are wiped out. In the chaos, Sheridan grabs the Device, steals one of the underground trains and takes off, having shot Hildra before she left.

BOOK FOUR

Avery, Layanna and Janx take the wounded Hildra to the second underground train and take off after Sheridan. Avery doctors Hildra while Janx drives. Avery manages to save Hildra, but Janx is angry at him. All of this is his fault. Because he wanted to save his daughter, ruin has been brought to them all. If Sheridan can manage to put enough distance between the two trains, she will be able to get away and bring the Device to her overseers. Octung will have won the war.

Instead, her train crashes into an enormous underground bug, which is blocking off the tracks. Avery and the others come across the wreckage, but her body and the Device is nowhere to be seen. They’re in the middle of an enormous alien-looking city far underground. Setting off into it, they quickly realize the city is inhabited by intelligent insect-people, who immediately try to kill the invaders. Avery’s group find Sheridan, still alive, if badly wounded, and in possession of the Device, and they fight the bug-people side by side, until it’s clear that the bug people are too many.

Reluctantly, Layanna summons Sartrand and his fellow Muugists, who arrive via some sort of teleportation device and repel the bug-people. It had been Sartrand who had ordered the bug-people to block the tracks. Sartrand demands Layanna hand over the Device. Sheridan manages to drive the Muugists back through their teleportation portal, which closes behind them. She’d been injured in the wreck and will die without medical help.

So, still in possession of the Device, she kidnaps Avery and takes off in the second train, stranding Janx, Hildra and Layanna in the strange subterranean city.

Avery and Sheridan, former lovers, reconnect somewhat as they hurtle along through the darkness. He doctors her back to health and she keeps him chained up. They cross beneath the borders of Octung and go far beyond, eventually coming upon Laisha, an exotic country occupied by Octung.

Finally Sheridan is able to hand the Device over to Octunggen authorities. Instead of having Avery arrested, Sheridan allows him to roam free. The two form an odd bond. Avery and Layanna had been on a break because of her refusal to forgo human sacrifice, and he and Sheridan resume their old physical relationship. On the side, he works with Laishan rebels to try to overthrow Octung and steal back the Device.

During a revolt organized by the rebels, he attempts to do just that, betraying Sheridan, but she had seen this coming and switched the Device with a bowling ball. He got away with the bowling ball while she retained the Device, which is to be taken to the Over-City, that great aerial construct of Octung, now approaching Laisha. Avery escapes, but in the chaos the locals take him for an enemy and nearly kill him; they’re massacring all the outsiders they can find. Luckily Janx, Hildra and Layanna finally show up and save him.

He discloses to them that Ani is aboard the Over-City, along with Sheridan and the Device. Sheridan had had Ani brought here to be given to Avery once the Device was aboard the Over-City. He’d given up having his daughter back for a chance at getting the Device away from Sheridan, thus partially redeeming his earlier mistakes. Layanna forgives him and they resume their relationship, although they have to hide out from angry Octunggen occupiers (who have retaken control of the city) in the meantime.

While Sheridan and the Device get away aboard the Over-City, Avery and the others are hunted. They find shelter with Layanna’s human son Frederick, who lives in an expatriate quarter of the city. He’s never forgiven Layanna for leaving his father, and he’s become a bitter junkie hooked on hava.

Determined to end the threat Layanna poses once and for all, the Octunggen occupiers bomb the city with an alchemical gas, causing strange effects among the populace. Octung sacrifices the entire city to kill Layanna.

BOOK FIVE

Avery uses Frederick’s addiction against him, and the group secures a dirigible, going after the Over-City and rising above the toxic gas. They infiltrate the aerial brothel known as Paradise, kidnap a high-ranking Octunggen officer and take possession of his aerial yacht, a very expensive dirigible.

In this, they pursue the Over-City and at last land on it, posing as loyal Octunggen. They rescue Ani and confront Sheridan, who informs them that Uthua is leading the ceremony that will activate the Device in favor of Octung even then. They have reached the sea and Octung has reversed the Device’s functions.

Avery, posing as Sheridan’s plus-one, attends the activation ceremony with her, having concocted a plan with the others. Sheridan is arrested at the ceremony but Avery is left free. Sartrand attends the ceremony, as well, and Avery tricks him, getting him to attack Uthua. While the two Collossum fight, Avery steals the Device and runs. He rejoins the others and they fly away with all the forces of the Over-City in pursuit.

Layanna restores the Device’s original functions just as the dirigible is shot down by Uthua. She prepares to activate the Device aboard the sinking ship when Uthua arrives in person. Sheridan, who is with them at the time, fights Avery while the others hold off Uthua. Frederick sacrifices his life to wound the Collossum, and Uthua is sent into the sea. Avery asks Sheridan why she’s siding with beings like Uthua, and she tells him it’s because she wants Octung to win; if it doesn’t, the R’loth will rise up and prosecute their war themselves, and it will be terrible. She begs Avery not to activate the Device or the world will suffer.

Ani shoots Sheridan. Avery activates the Device. The Over-City falls. The War of Octung is over. But Avery knows that Sheridan is right. Now the R’loth, denied their puppet Octung, will act themselves. Avery braces himself for the worst.

BOOK SIX