Sarah Roberts receives a phone call from her colleague Parkman. It's important they meet right away as it's a matter of life and death. Because Parkman is a close friend, Sarah ignores a warning from her dead sister Vivian to stay away. When Sarah is shot, Parkman fires on the retreating four-door sedan, but is not successful in stopping the shooter. He attempts to revive Sarah until the paramedics arrive to take over. When Parkman gets to the hospital, the police question him about who really shot Sarah. After emergency surgery to remove the bullet and reduce the swelling on Sarah's brain, preliminary results show the bullet came from Parkman's gun.
He asks to visit Sarah in the ICU, but now no one can find her. He is informed that Sarah Roberts was never admitted to their hospital and the doctor Parkman was talking to earlier about her condition has mysteriously disappeared.
Sarah is gone.
When Sarah wakes in a modified ambulance, far from the hospital in Toronto, she has retrograde amnesia, leaving her with temporary short-term memory loss. All she can remember of the night she was shot is the image of a man named Parkman. He is standing in front of her with a gun in his hand as a bullet enters her head.
The people who shot Sarah are still after her. She needs to work with Parkman in order to stay alive, but all Sarah can think about is revenge for the head wound and Parkman is in her sights.
The pain of betrayal goes deeper than the physical wound as Sarah hunts for her former friend while sorting the memories that return in pieces.
Killing Sarah is an explosive ride into the depths of a strong woman who makes mistakes and learns the consequences the hard way.