A young, single mother who is struggling to make ends meet goes missing after dropping her son off at the babysitter. While the team struggles to find out what they can about the young woman's personal life, Sam feels the case is hitting very close to home. They soon learn of a drug smuggling gang and an ex-con who is connected to other unusually similar cases of missing women. The team plans to bust him on every charge possible, but at a very dangerous price.
Sam volunteers to go undercover to bust a ruthless drug smuggling ring, which the team believes is directly connected to the disappearances and murders of different women. Sam's difficult past is revealed, and despite warnings to get out, she becomes dangerously involved in her undercover investigation, which quickly turns into a life-or-death hostage situation.
When a 13-year-old girl goes missing after choosing to investigate the age-old murder of a different teenage girl - taking suspicion off of the original suspect and placing it on her own father instead - the team races against the clock to find out what happened to Daisy and if her father, who turns out not to be so innocent, truly plays a part in both his daughter's disappearance and of the murder of Amber Bryce, a years-ago unresolved case.
An old man estranged from his wife and two daughters goes missing after last being seen ready to jump from the roof of his building. Jack gets personally involved in the case and trying to find the man.