Surrounded by colleagues who know her to be the suspect in a murder, Sarah keeps her demons at bay by involving herself in the troubles of strangers. Seventeen-year-old Aidan Hennessy was banished from his family by his father. Now Aidan's twin sister is desperately searching for the brother she hasn't seen in years. Although the case is out of Sarah's jurisdiction, she sees a reflection of herself in the troubled, damaged family, and agrees to investigate.

As she probes into their tangled history, Sarah begins to realize that the mystery of the Hennessys runs deeper than it appears. Then Sarah's lieutenant gives her a simpler assignment: Track down a doctor rumored to be practicing medicine without a license in a housing project. But in Cicero Ruiz, Sarah finds a tough, wounded survivor whose moral code challenges her own ideas about justice...and whose hard-won life would be destroyed by an arrest.

Now juggling two very different cases, both requiring a delicate balancing act between professional honor and personal feelings, Sarah soon has even more at stake. Caught up in a cat-and-mouse game with the investigator who wants to end her career, crossing one ethical line after another, Sarah increasingly fears that a misstep on her part will end not only in her disgrace, but in the death of one of those she has promised herself to protect.