You know what I like about books that have no words? The illustrations have to be good to carry the story. Creepy Castle by John Goodall delivers on the gorgeous illustrations. They're colorful and detailed.
Two mice - a princess and her knight, perhaps? (That's the other thing about narration-less books, you kind of make up your own story.) - go exploring in a creepy, abandoned castle. They are followed by a malicious rat and the adventures keep coming page after caption-less page.
This one is a current favorite of the two Bigs. I may have to return the library's copy and go on a hunt for our own.