On his first day back from leave, widowed cop Sam is called to the scene of a young woman's murder, where he clashes with rookie tech whiz Billie.

A graphic assassination video posted online leads the team to a network of ISIS recruiters in a case that strikes a nerve for Nassim.

When a hidden camera in the woods captures the slaying of a hacker known for exposing corruption, Billie tries to conceal her link to the victim.