S3, E9: After the officers of 15 Division are forced to release a suspected predator, the grim discovery of the body of a missing girl reopens an unsolved case – bringing back Detective Luke Callaghan in from the Homicide Squad to oversee it. But when they learn that Andy has been assaulted, and Gail Peck has been violently abducted following the call-girl sting, it's a race against time as the officers of 15 Division work frantically to recover one of their own