Watchmaker Hermux Tantamoq is a hard-working mouse who is thankful for the ordinary things in life: doughnuts, coffee, peaceful evenings at home with his pet ladybird. But his quiet life takes a dramatic turn when Ms Linka Perflinger, dashing daredevil, aviatrix and adventuress, bursts into his watch shop, drops off a broken watch and steals his heart.

Hermux can't wait to see Ms Perflinger again, but she doesn't return. Instead, a shady-looking rat comes in and demands her watch. Fearing something is amiss, Hermux follows the rat and soon finds himself in the middle of a dangerous web of deception and intrigue. What has happened to Ms Perflinger? Who is the mysterious Dr Mennus he keeps hearing about, and how is he connected with Hermux's eccentric neighbor, cosmetics tycoon Tucka Mertslin? Suddenly, Hermux's life is full of twists and turns and things are anything but ordinary.

Hermux must be daring. He must be vigilant. And he doesn't know how. But as sure as corn is sweet and cheese goes mouldy, Hermux must rescue Ms Perflinger and, in the process, must find out just what kind of mouse he really is.