Mr. Putter is convinced to run in a senior marathon with his neighbor, Mrs. Teaberry, when he learns that second prize is a train set.

Thirteen-year-old Theo, overweight and out of shape, finds that with his friend's support he just might be able to run in the race to raise money to help cancer patients like his aunt.

Wiglaf and his classmates come to appreciate their elders when they learn that only a group of retired knights can save their school from the world's oldest living dragon, Grizzlegore--if they can get back in shape in time.