In Lancaster, Pennsylvania, Derrick meets the Hicks family and builds a custom prosthesis for their dog, Millie, who was born with a front limb deformity.

Derrick helps a pup named Rosie who is missing a paw and needs a custom prosthetic. Then, Derrick travels to Los Angeles to meet a chihuahua named Roo, who was born with two legs and needs a custom cart to help her keep up with her best friend, Chase