Harry Bosch is back as a volunteer working cold cases for the San Fernando police and is called out to a local drug store where a young pharmacist has been murdered. Bosch and the town's three-person detective squad sift through the clues, which lead into the dangerous, big business world of prescription drug abuse. Meanwhile, an old case from Bosch's LAPD days comes back to haunt him when a long-imprisoned killer claims Harry framed him and seems to have new evidence to prove it