After teenage outcast Velma Dinkley is accused of killing a popular classmate, she has just 24 hours to find the real murderer. There’s only one problem: Velma has sworn off solving mysteries – forever.

After finding themselves trapped in a cave, Velma and Daphne are forced to confront their complicated relationship. While Fred proves he really does love women for their brains, Gigi vies for Norville’s attention.

Given 72 hours to uncover the identity of the serial killer, Velma is forced to live a lie with Norville, while Daphne and Fred concoct a story of their own to get back in with the Brains.

While Velma races against the clock to find the true serial killer, Daphne pursues a new career path, Fred finds a way to channel his rage, and Norville attempts to get as far away from his former best friend as possible.

Velma clashes with Fred over whether the crimes plaguing Crystal Cove are of this Earth. Later, Daphne and Amber make a grisly discovery.

Velma resists the urge to cash in on Diya's new relationship, while Norville searches for a way to stop his hallucinations once and for all.

While attending a career fair, Velma begins to doubt her dreams – until a mission to help the Brains reignites her passion for chasing clues.

When a masked assailant threatens her family, Velma vows to get to the bottom of Project Scoobi and bring down the killer.