Whats that story!

[Enoch]

The plot goes something alike there is a camp with a girl has gone to. On this camp not everything is right. In the woods outside the camp a fence is put up and she doesn't really know why. But outside the fence some kind of beast. This beast reminds of a huge cat (if I remember correctly) and it is trying to get in.

In the end it turns out it was trying to get to a creature held in a chest or box at the camp by one of the leaders (I think) that was some kind of... rat, or spider... yeah...

I need help figuring it out for a friend, so anyone know?