After a furious debate over their fitness levels, Colin and Tom decide running the 26.2 mile London marathon would be a bit of a stretch so instead challenge each other to drink 26.2 pints of lager the fastest with a twelve hour time limit. Colin enlists the help of boozing expert Tony 'The Duke' Burton to train him for the forthcoming battle but foul play begins to play a part as they meet Tom in a pub beer garden for the competition.