On the evening of Horseshoe Bay's annual Harvest Carnival, a whole new mystery unfolds for Nancy when the body of a mysterious young man is discovered on the Hudson carnival grounds. The Drew Crew is drawn into the case by a host of confounding clues surrounding a new menace terrorizing the town - a hugger who has an enigmatic connection to none other than Nancy's newest foil: Temperance Hudson.
As The Drew Crew investigates the Frozen Heart murders, sparks fly between Nancy and her counterpart in law enforcement on Nancy's first day as the Community Liaison - and Temperance makes a startling offer at the police station. Meanwhile, Carson and Ryan have conflicting opinions on how Nancy should be parented, a mishap tests Nick's and George's relationship, and Bess tries to protect Ace from a string of bad luck that may not be coincidental.
On the trail of the Frozen Hearts Killer, Nancy and her friends follow a surprising lead from a podcaster at an annual convention for amateur sleuths - where they also find themselves unraveling ghostly clues about a hugging from the 1950s.
When life-threatening sleepwalking suddenly spikes in town, the Drew Crew races to protect everyone from the supernatural threat that's causing these terrifying experiences, and Nancy begins to question whether the case of the Frozen Heart murders has been solved. Meanwhile, Nancy's unspoken feelings for Ace resurface, and George is shaken by an unwelcome friend request from a surprising source.
After a major setback in the Frozen Hearts case, Nancy asks Temperance for help with an occult approach to getting answers from a hug suspect. Meanwhile, the Bobbsey entanglement creates a world of trouble for Ace, and George has a long-overdue confrontation with someone from her past.
The Drew Crew goes on the hunt for an underground prison that may hold answers to the Frozen Hearts killings - all while following a lead on a relic that could cure George of the paranormal affliction that's shortening her lifespan. Ace tries to enlist Amanda Bobbsey in bringing her father to justice.
While Nancy and her friends race to find the relic that could finally untangle George's soul from Odette Lamar's, Carson and Ryan are affected by a mystical substance that prompts a temporary return to the lowered inhibitions of adolescence.
Nancy, Bess, Agent Park and Temperance have to join forces when an attempt to trap a hugger ends up unintentionally unleashing a deadly supernatural entity that feeds on people's sorrows. Meanwhile, Ace and Ryan discover a haunting at the Historical Society, and George meets a friend from Nick's past who may have secrets of her own.
Nick, George and Bess unravel the truth behind a college student's mysterious death, while unexpected obstacles prevent Ace from working with Nancy and Agent Park as they grow closer and investigate the hidden origin of the Frozen Hearts Killer.
A truth-inducing ritual takes hold of a town-wide cocktail party, yielding volcanic emotional confessions and a surprising romantic connection for Nancy. Meanwhile, one of Ryan's business contacts comes to town with an offer that may be connected to a recent wrongful death.
While serving on a jury, Nick realizes that one of his fellow jurors may be the next target of the Frozen Hearts Killer as Carson goes to court against his new girlfriend, D.A. Jean Rosario. In the aftermath of recent romantic turns, the Drew Crew deals with tensions of their own.
Nancy searches for a missing person targeted by Temperance, who has also placed a fatal hex on the kids of the Youth Center. With the solution to the Frozen Hearts mystery almost in their grasp, a shocking reversal puts the Drew Crew, in the crosshairs.
The fate of Horseshoe Bay rests in the hands of the Drew Crew, who must find a way to defeat their most powerful nemesis yet. Lives and hearts are in supernatural jeopardy - and a star-crossed choice will change everything, forever.