The Monroes have gone on vacation, leaving Harold and Chester at Chateau Bow-Wow -- not exactly a four-star hotel. On the animals' very first night there, the silence is pierced by a peculiar wake-up call -- an unearthly howl that makes Chester observe that the place should be called Howliday Inn.

But the mysterious cries in the night (Chester is convinced there are werewolves afoot) are just the beginning of the frightening goings-on. Soon animals start disappearing, and there are whispers of murder. Is checkout time at Chateau Bow-Wow going to come earlier than Harold and Chester anticipated?