"Neither of us are likely to make it through without the other. If you want to race my friends, you're going to need me." A magical source of power, sealed away in a deadly labyrinth. Trials, designed to judge the character of those trying to reach their prize. A murderer, on a mission to make it through a system designed to keep her from ever succeeding. A lot can go wrong in places of old power. Lark knows from the moment they step inside the labyrinth that it is going to be a mess of a day, because it always is if their murderous ex, Nightingale, is involved. What they don't expect is to get stuck alone with her.

Forced to face everything that has gone wrong between them, Lark and Nightingale must navigate the labyrinth and each other in order to make it out alive.