On Sarah’s birthday, her best friend Victoria gives her a genetic testing kit as a gift, so she can learn more about her family’s lineage. But that night, Victoria is tragically killed. Weeks later, Sarah gets on knock on her door, and it’s the police. As their homicide case ran cold, they decided to run the killer’s DNA through the genetic testing site’s database and there was a match: Sarah. It turns out that someone related to Sarah killed her best friend… but who's?

The devious Dr. Albert Beck finds his latest stalking victim after changing his identity and beginning work at a sleep clinic.

Called to mourn the passing of their beloved detective grandfathers, Nic O’Connell and Ping Liu soon discover that their deaths were calculated murders. Despite their mutual animosity, the granddaughters enter an uneasy partnership to solve the case.