On the evening of Horseshoe Bay’s annual Harvest Carnival, 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 killer who has an enigmatic connection to none other than Nancy’s newest foil: Temperance Hudson.

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 homicide from the 1950s.

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 killer 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.

A truth-inducing ritual takes hold of a town-wide cocktail party, yielding volcanic emotional confessions and a surprising romantic connection for Nancy.

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.

Nancy launches a new investigation to find a group of missing bodies from Horseshoe Bay's cemetery that have been dug up and stolen – or have possibly risen. As Nancy is drawn into this ghostly case, a string of unexplained paranormal crimes leads the Drew Crew to believe that the literal sins of the town's past have returned to haunt the living. Meanwhile, Nancy struggles with yearning for Ace, the man she loves. But when a slow-burning attraction begins between Nancy and the son of Ryan Hudson's newest enemy, Nancy must decide whether this love interest is worth the ire of both her father and Ace – whose own heart may be tempted by a new relationship too.

Ace senses that Nancy is holding back and presses her to give him more information about the curse. Meanwhile, Bess is determined to prepare the perfect meal for Addy’s parents, and Nick schedules a brunch date with someone new. Lastly, George’s plan to let Judge Abbot know how grateful she is for the opportunity to be his clerk takes a shocking turn.

Nancy and the Drew Crew prepare to battle a Sin Eater.

Nancy and the Drew Crew’s mission to save Horseshoe Bay from sins of its past comes to an epic conclusion as they must contend with Nancy’s most shocking discovery yet, one that will determine the fate of her star-crossed love with Ace.