Boris is a mouse who lives on the London Underground. He shares his station with wise grandfather Garibaldi, his swaggering cousin Kicker and his best friend, Heavy Duty, the station cleaner. Kicker and Boris love football and when they see a brand-new football rolling down the station platform towards them, they can't resist the temptation to start a game. Their footballing exploits end up taking them all over London on their biggest adventure yet.