In Incarceron, a vast intelligent city-prison sealed off from the outside world and hidden from everybody except the Warden, two young people, Cynthia, the Warden's daughter who is trying to esacape an arranged marriage, and Finn, a young prisoner who cannot remember his childhood, join forces to attempt to escape.

Sixteen-year-old Sarah sells her soul to reclaim her family's estate and is given 100 years to atone for their sins, but as the bargain nears its end, modern-day Tom, yearning to attend the private school that Darkwater Hall has become, gets caught up in the bargain.