After Shani mistakenly blames Polly for using the locket's power to get an unfair advantage in the science fair, Shani impulsively throws her own project into the trash - and now the girls must retrieve it while staying one step ahead of Griselle.

Polly and friends want this to be the best Halloween ever, but Griselle puts a kink in their plans when she goes undercover in the Haunted Hayride to steal Polly's locket.