It was supposed to be a year to remember for seniors Sofia Schultz and Carmen Hernandez. But when weird things start happening around Foggy Creek, they quickly realize that it will be a memorable year–if they survive! Strange power surges, a missing cat, spooked horses, and mysterious tracks lead the friends to eerie sinkholes. There, they find giant tarantulas that will feed on everything they can get their hairy legs on. Can Sofia and Carmen stop the mutant creatures?