It's carnival time! Paddington Bear and his friend Mr. Gruber join the festivities by entering the Busy Bee Adventure Trail contest--whoever finds the greatest number of objects starting with the letter "B" wins a prize. They search all along the canals of Little Venice in London where Bicycles, Boats, and Balloons abound. Things couldn't be better. Then Mr. Gruber notices a sneaky-looking boy following them, . Could he be copying their list? Luckily, Paddington has a trick or two up his sleeve....