The Loophole

Ren Trayger gets his friends together to show them a blueprint of a treehouse they want to build. They venture into the forest, seeing a tree with a root growing from its side, curving into the ground. One of the kids goes underneath the root, going around the left side only to disappear. The root is the opening to a slow descent into a hell where shadows flow like water, and they need to fend them off with a source of light in order to survive. With bits and pieces slowly getting taken by the shadows, it's only a matter of time before the boys are too corrupted to return to their home world.