Former police detective Carrie Wells has a rare medical condition that enhances her ability to remember so much that every occurrence, every conversation, every place is forever embedded in her mind. She doesn't choose what to remember; Her mind won't let her forget anything - with one exception. Carrie's sister was murdered years ago, except she can't recall any of the details that would help to solve it.

After taking a job consulting on a homicide investigation, she decides to permanently join the force again as a detective solving homicides - with the goal of finally solving her sister's murder. All she has to do is remember.