Dr. Kate Blunt will do anything for her son, Jasper. Well, almost anything. Since Jasper has the incurable lung disease cystic fibrosis, Kate’s always told him he couldn’t get a dog. It’s a tough call, but she’s a single mom taking care of a kid who fights for every breath he takes. The daily medical routine that keeps Jasper alive is complicated enough. Worse still, Kate’s personal resolve runs contrary to her work as the veterinarian in charge of a Cape Cod animal shelter, where she is on a mission to find forever homes for dogs in desperate need. Whistler, the scarred, mistreated wreck of a dog that turns up, forms an instantaneous bond with Jasper, who would do anything to find him a home. But Whistler has chosen them --- for a reason.