Antonia Scott is the most intelligent woman in the world –a virtue and a curse at the same time. Her intelligence allowed her to become the "Red Queen" of a secret experimental police project. But a personal tragedy removed her from active duty. Now, Jon Gutiérrez, a police officer in trouble, has to get her out of her seclusion to solve a case that will put her abilities and her past to the test.

Ezequiel has assassinated Álvaro Trueba and has kidnapped Carla Ortiz, both the firstborn of the most powerful families in Spain. Jon agrees to be Antonia's squire. Even though they started off with the wrong foot, they're about to catch Ezequiel after a fast-paced chase that has everyone on edge. In her cell, Carla finds out that she is not Ezequiel's only prisoner.