Detective Casey Schraeger (Amber Tamblyn) has just been transferred to the NYPD's Homicide unit and quickly finds that the force is full of secrets — and she has a few of her own. Her first case is not easy: she's assigned to investigate the death of one of the unit’s own, the former partner of Jason Walsh (Jeremy Renner), who is now her partner.
As they seek out the killer, the oddities of the unit emerge: Eddie Alvarez (Kai Lennox) has no qualms about stealing cases if he can turn them into front-page stories. Partners Eric Delahoy (Adam Goldberg) and Leo Banks (Harold Perrineau) are polar opposites; one is trying to kill himself and the other won’t remove his bulletproof vest. Henry Cole (Josh Close) is trying to keep his past from his streetwise partner, Allison Beaumont (Monique Gabriela Curnen), and Sgt. Brown (Terry Kinney), who is struggling to rid the precinct of corruption.