Knapsack
In Book 4 Kendra escapes being kidnapped with the aid of a magical knapsack. It contains an extra-dimensional space, a small hidden room accessed though the flap and down a ladder. It is large enough to keep storage, or hold several people at a time. Once inside the knapsack the occupants will feel no movement or jostling. In Fablehaven: Secrets of the Dragon Sanctuary, the knapsack is burned, with Warren still in it, sealing the entrance to the extra-dimensional space. In Book 5, Kendra returns to the knapsack with the help of the Translocater, one of the 5 artifacts, to rescue him.
Read more about this topic: List Of Magical Items In Fablehaven