Sam, a shy but creative mouse who lives in a library, decides to write and illustrate his own stories which he places on the shelves with the other library books but when children find the tales, they all want to meet the author.

"Fribble Mouse's neighbor, Mr. Crumb, is taking up a new hobby. But Mr. Crumb is keeping it a secret until he learns how to do it--unless Fribble can use his library know-how to crack the mystery first"--Page 4 of cover.

Fribble's birthday present from his grandparents is a letter containing a secret key that unlocks a series of mysteries that lead Fribble straight to the library.