Dez has one dream: to become a Guide Dog when he grows up. Unfortunately, he has to pass a whole set of difficult exams, and he's always being told off for tripping over and messing things up. Even with his best pal Stan to guide him, he soon realizes that becoming a Guide Dog is a lot harder than he originally thought. Meeting lots of interesting canine friends along the way, Dez finds out that passing exams is just one part of the puzzle. Becoming Man's Best Friend is a whole other problem.