Thirteen-year-old Anya Sullivan dreams of being an actress. Her twin, Austin, loves creating his own superhero comic books. While out by the pond in the woods, taking reference photos for Austin's newest comic, the twins discover a hole that has been covered up for more than a hundred years. Wondering how deep it is, Austin drops a plank of wood down the hole. They hear no echo, and guess it goes down a very long way.

The twins think little about it and leave the pond. However, the very same plank of wood shows up that night at their home. Did Donnie Kent, the creepy neighbor kid, manage somehow to pull it out and then leave it where the twins could find it in hopes of scaring them? Or...did the plank crawl there on its own?

Over the next two days, things that shouldn't be alive become alive, and some of the things are terrifying and vicious. Researching on the computer, Austin and Anya learn about the scientist who, long ago, had owned the land with the pond. And he knew the dark secrets of the mysterious, deep hole. But before the twins can properly seal the hole up again, Anya finds herself in a terrifying situation in which only her courage, and skill as an actress, can save her from certain doom.