Fallen Domain by T. W. Iain

Can old adversaries become allies?

Rodin knows Authority must be stopped, and that means returning to the Dome. But the only one who knows a way in is Cat, the one-time Authority agent who has been manipulating Rodin for years, playing with Rodin's life for his own suspicious ends.

To the south of the Dome, Authority relentlessly push Genna back, forcing a retreat into the heart of her district. Soon, she will be surrounded and outgunned. But there's one man who could help – the same man who once betrayed her, who was responsible for the near-destruction of her district, who stood by and watched as she was tortured close to death.

With so many lives at stake, can Rodin and Genna do the unthinkable and work with their enemies?