Matilda, a small lighthouse mouse fixated on the tedious routine of life, finds herself in a predicament that forces her to enact the lessons that her parents instilled in her. Mr. Berryfoot, the lighthouse keeper, has lost the last working lighthouse fuse, forcing Matilda to abandon the security of her home to retrieve the missing fuse. In doing so, Matilda helps save individuals of another species, although her fears and instincts tell her to do otherwise. By locating the errant fuse and befriending the once frightening lighthouse keeper, Matilda realizes being small may mean you're just the right size for a big job.