Basil leads an expedition up a towering Swiss mountain in search of a colony of mice who have been missing for centuries, but before he can solve the mystery he must confront a mysterious snow mouse and evil Professor Ratigan.

Headed for the Grand Canyon to investigate a mystery at a hotel, Basil finds himself involved in dangerous adventures as he tries to foil the schemes of a ruthless smuggler.

"With Sherlock Holmes away on a case, Basil and Doctor Dawson find themselves at loose ends until an urgent message arrives: Basil's services are required by the noblemice of Marlborough House! Marlborough House is the home of Edward, the Prince of Wales (second child and eldest son of Queen Victoria) who lives there with various children and family members. Unbeknownst to the human royals, there is a corresponding clan of noblemice living there as...

A French mouse decides to earn an honest living by tasting the cheese in a cheese factory and leaving notes about its quality.