While investigating the homicide of an overzealous journalism student, Jane is not happy when a former colleague returns to BPD as the new lieutenant of the drug unit. But the murder she's investigating soon forces her to deal with him - and the event that wrecked their relationship. Meanwhile, an alarming tip from Cailin causes Maura to investigate Hope.

Maura becomes the key suspect in a homicide case when Maura's date turns up dead - and Maura can't remember their evening together. As the shocking evidence against Maura piles up, Jane struggles between protecting her best friend and doing her job.