A few years ago, Mustang Sally had to make a deal with her worst enemy in the entire world: Destroyer, the man who killed her father. He agreed to use his technology to reverse a nanotech plague and save the world. His price? A favor, to be collected from Sally at some point in the future.

The time has come for Sally to fulfill her obligation. Destroyer needs her to help him save the life of his sister, who has been trapped in a comatose state for nearly her entire life. Sally will have to enter the woman's Dream-world,...