Book excerpt: Today, Wallace is a champion; but in the summer of 2005, he was living in a shelter, a refugee from a suspicious pit-bull breeding operation. Then Andrew "Roo" Yori entered the picture. A scientist and shelter volunteer, Roo could immediately see that Wallace was something special. When Roo learned that Wallace was about to be put down, he and his wife frantically fought to keep Wallace alive until they could adopt him, even though they already had two dogs. Once Wallace made it home, Roo knew the dog needed a mission, and serendipity led them to the world of competitive dog Frisbee. Pit bulls are everything that most Frisbee dogs are not, but that was fine with Roo because part of his mission was to change people's minds about pit bulls. Overcoming everything from injuries to prejudice against the breed, the unlikely pair persevered to become world champions.