Neuropsychiatrist Cristina Silva is haunted by her past. She can't escape the voice in her head of her former identity, and she can't forget her ex-boyfriend, police detective Gary Wilson.
When Cristina starts a new job at the Longwood Memory Center, she receives a disturbing phone call from her FBI contact. An assassin is killing people who were connected to the pharmaceutical company ReMind, and Cristina is one of the targets.
The assassin is a woman known as Dama Branca, and she has also been affected by Zero Dark. She's not sure why she's not killing Cristina, but she's drawn to the brilliant doctor.
Meanwhile, Wilson is investigating the suspicious deaths of local teens. He believes they're not accidents, and he's determined to stop the killer, who he's dubbed the Sack Man.
As Cristina and Wilson's stories become entangled, the danger escalates. With at least one killer in their wake, they must quickly figure out what's real and what's not. Unlocking Cristina's memories could save many lives, including her own.