After three years infiltrating the Crown's intelligence network, followed by a long and treacherous journey home, Farris has finally arrived at Penance: the Simian City of Steam.However, much has changed while he was away. Where he was once at the right hand of the Silverback - the leader of the Simian separatist movement - now Farris watches from afar as his old comrades whisper in the shadows about secret plans and advanced weaponry.Meanwhile, the Sons of Seletoth, a fringe religious sect, has suddenly come to prominence. The ruined Tower of Sin, once the epicentre of Simian ingenuity, now houses these preaching fanatics and their many followers. Worse still, the once atheistic Silverback has now aligned himself with these zealots, but to what end?Now, Farris has found himself distanced from the separatist movement at this critical time: the Human kingdom has already attacked Penance, and the Simians are ready to march....

After defeating the undead horde at Penance, the City of Steam, Simians and Humans alike celebrate their victory. Their home has been saved, and Morrígan, the leader of the invading army, has vanished. But Farris does not share the same optimism as his people. He saw what happened the night the undead came: Morrígan killed King Diarmuid, claimed his power for herself, and transcended to demi-godhood. Now, she seeks the two other gods of the Trinity: Lady Meadhbh, who dwells deep in her underground tomb, and Lord Seletoth, a mighty, reclusive god who lives atop the lonely peak of Mount Selyth. In order to stop Morrígan, Farris needs to convince the fragile governing body of the Triad to send their army away from the city. But Penance is still recovering from the battle with the undead, and King Diarmuid's death has left an empty throne and a council in disarray. Furthermore, law and order has broken down in the city, threatening its waning resources...

Morrígan wants to become a mage, but her uncle, Yarlaith the White, refuses to train her.Of course, he doesn't understand that the world is more dangerous than ever. Only days ago, her mother was killed by a mountain troll, and Morrígan was helpless to intervene. Now, a small army has stationed themselves in Morrígan's village, sent by King Diarmuid. He claims that the Simian rebels to the north are threatening to attack the Human kingdom with their advanced weaponry, but there are some who question his motives.Either way, machines are no match for magic, which is all the more reason for Morrígan to learn....Meanwhile Farris, a Simian double-agent, uncovers plans that King Diarmuid is planning a pre-emptive strike on the Simian City of Steam. Farris embarks on an intrepid voyage across the kingdom, where he must choose between siding with his own people or preventing a brutal civil war.