Sybil (guest star Nathalie Kelley) enacts revenge on Damon (Ian Somerhalder) by putting him in a catatonic state. Caroline (Candice King) and Bonnie (Kat Graham) enter Damon’s mind and run into familiar faces from the past, only to discover Stefan (Paul Wesley) is the key to Damon’s fate. It’s a race against time for the bell as both Sybil and her sister Seline (Kristen Gutoskie) jockey for its control. Zach Roerig also stars.
Riggs is reunited with childhood friends and comes to realize they might be mixed up in the robbery-homicide case he and Murtaugh are investigating. Meanwhile, Murtaugh finds a joint stashed in his kitchen that he brings to Scorsese for testing in effort to bust one of his kids.
It's Christmastime and the Murtaugh family is headed to Hawaii. However, Murtaugh's vacation is put on hold when he and Riggs are called to a homicide and the victim is an old friend. Meanwhile, Riggs gets a surprise phone call from a relative just in time for Christmas.
Riggs and Murtaugh are thrown into the world of counterfeit money. When a group of teenagers inadvertently gets involved, it strikes a chord with Murtaugh, who is dealing with his own issues regarding his son, RJ. Meanwhile, Riggs decides to pay a visit to someone from his past.
Riggs and Murtaugh are drawn into a fatal world of conspiracy theories. Meanwhile, Riggs’ relationship with Molly evolves and Murtaugh and Trish attempt to get Harper into a fancy pre-school.