Charlotte Alton is an elegant London socialite. But behind the locked doors of her sleek, fortified apartment, she becomes Karla, a fixer who specializes in creating and erasing identities, and can cover any criminal’s tracks. Only a few people in the world know her secret.
 
One of them is Simon Johanssen, a killer-for-hire who resurfaces—years after she helped him to quietly disappear—with an impossible job. He needs access to a high-security, experimental prison colony in order to assassinate an inmate. The catch: there’s no record of the target’s existence, and what’s worse, the criminal boss from whom he’s been hiding is inside, too. The trap has been set, but who is the real target—Johanssen or Karla herself?