Deterioration

Cynthia Carter runs into her old best friend, Keira, in the most bizarre way. Turns out, Keira is part of a serial-killer duo that the police have been chasing down for a few years.

When confronting her old friend, Cynthia learns that it's hard to see how people from the past have changed. She learns about what turned her friend to this while simultaneously trying to uncover the identity of Keira's accomplice.