Dylan and Lizzie investigate the murder of a successful businesswoman who attempted to prolong the lifespan of humans. Also, Dylan and Andy look to continue their adoption search, and Detective Ryan Stock from Nebraska arrives to hunt for a potential serial killer.

Dylan and Lizzie investigate the murder of an aspiring musician who was gunned down on a roller coaster at an amusement park. Also, Lizzie exhausts herself trying to keep up with a newly single friend, and Andy and Dylan look to broaden their options for adoption.

Lizzie and Dylan work a case that provokes deep emotions for them when a 9-year-old boy goes missing on the eve of a judge’s decision in a bitter custody battle. Also, with Dylan’s help, Lizzie confronts some of her past childhood demons, and a major advancement presents itself in Dylan and Andy’s adoption search.

A Sweet 16 celebration turns into a crime scene when the birthday girl’s stepmother falls to her death and the guests and staff are put under a microscope by the NYPD. Also, Ryan finds a new lead in his investigation, and Lizzie receives some positive news at the precinct.

Dylan and Lizzie investigate the case of a prominent divorce lawyer who is found murdered in a bizarre ritual. Dylan and Andy hit a bump in their adoption process. Lizzie and Julian reach a tough point in their relationship. Ryan’s serial killer case escalates.

Dylan and Lizzie investigate when a street artist’s work is found with a victim’s body in the middle of it. Also, Ryan catches a suspect in the Sleeping Beauty Killer investigation and Dylan’s new book editor, Harry Kassabian, pays him a visit.