Ben is stuck in a backwater town, his parents have broken up, and he's facing jail time for some very poor choices. Essa is stuck in a backwater world, trapped by a vengeful ex-lover and cut off from the Well, the infinite pit lined with doors to countless realities. Then Essa finds a way back, and drags Ben along with her. They learn an ancient threat to the Well is rising. On the run, their only allies a clockwork spider and a girl made of iron, they'll have to work together to save all the worlds.