Welcome to Ratbridge. But beware--for there is skulduggery afoot. Young Arthur has fallen foul of the appalling outlaw, Snatcher, and is trapped alone in the town with every way home sealed. Meanwhile Snatcher and his men are working tirelessly in secret on a fiendish and dastardly plan to destroy the entire town.

With the help of some friendly boxtrolls and cabbageheads, some quirkly townspeople, and the rats and pirates from the Ratbridge Nautical Laundry, can Arthur thwart Snatcher's evil plans and find his way home?