Summer is back in Boston, bringing with it the anniversary of a protest that turned into a massacre. It's a somber occasion, but one that blends into the sea of police brutality incidents across the country for Agent Luis Gomes - until his partner, State Police Detective Donovan Carey, is accused of a terrible crime.

Donovan knows he was nowhere near the crime, but eyewitness testimony is conflicting and unreliable. His own agency is desperate to be seen doing the right thing after a string of scandals and is more concerned about regaining public trust than about facts.

Luis is assigned to investigate the case. Can he put aside his love for Donovan and find out what really happened? And when he does, will he be able to hold onto the principles he's believed in since childhood?

Prodigal includes discussion of police brutality and of Bostonians rioting, which has been a popular pastime since the late 17th century.