by Margery Sharp, Garth Williams
5 out of 5 stars on GoodReads
Bernard must persuade Miss Bianca to help the Prisoner’s Aid Society in finding a Norwegian mouse who will bravely rescue a Norwegian poet from the cold dungeons of the Black Castle. Once she finds the courageous Nils, a seafaring Norwegian mouse, Miss Bianca is swept along in the adventure, and the three unlikely companions are tested to the limit of their abilities in the Black Castle. No mouse has ever freed a prisoner before, but these clever mice are determined to save the poet!