In the wake of tragedy, LBPD training officer Traci Harmon takes on new trainee, Alex Diaz who on day one is already learning the job is harder than he imagined.

Diaz learns that Harmon has enemies within West Division, and begins to fear she cannot be trusted.

Back on patrol, the rift between Harmon and Diaz comes to a head.

A shot caller's revenge mission results in West Division going head to head with an entire gang.