Detective Renée Ballard is working the night beat and returns to Hollywood Station to find a stranger rifling through old file cabinets. The intruder is retired detective Harry Bosch, working a cold case that has gotten under his skin. Ballard can't let him go through department records, but when he leaves, she looks into the case herself and feels a deep tug of empathy and anger. The murder, unsolved, was of 15-year-old Daisy Clayton, a runaway on the streets of Hollywood who was brutally killed. Now Ballard joins forces with Bosch to find out what happened to Daisy, and to finally bring her killer to justice. But this new partnership is put to the test when the case takes an unexpected and dangerous turn.