1836, a world of light and dark, noble and guild. The two spheres intersect when seventeen-year-old Allie Donovan is placed at the aristocratic St Matthews Academy. More at ease with a blade than a needle, she finds herself ostracised by the girls and stalked by a Scottish lord intent on learning why she is among them. She begins to suspect why she is at the school when soldiers arrive to see her friend, Zeb, a mechanical genius. On the hunt for answers she breaks into his underground laboratory. There, Allie discovers he is not just constructing sentient mechanical creatures, he is building a devastating new weapon for the military. Used to relying on herself, Allie must cross the guild-noble divide to keep Zeb safe and stop the weapon falling into the wrong hands. However, the guilds want the device and she is caught in their trap. Once rescued from Newgate prison, now she must obey the overlord of the guild and deliver up her friend or he will return her to the gallows. Can she trust her new bonds of friendship to save both their lives?