During their final summer at Camp Ruby-Spears, old friends Shaggy (Tanner Hagen) and Daphne (Mckenna Grace) get embroiled in a haunting mystery surrounding a lonely lost Great Dane puppy (voiced by Frank Welker) that may have been a witness to a supernatural murder. Together with the pragmatic and scientific townie, Velma (Abby Ryder Fortson), and the strange, but ever-so-handsome new kid (Maxwell Jenkins), Freddy, they set out to solve the case that is pulling each of them into a creepy nightmare that threatens to expose all of their secrets.