 Six-year-old Jenny (Natalie Wood) rescues a collie dog, the only survivor of a plane wreck. A tag on the dog s neck states that it is en route to a medical laboratory where its blood will be used for spotted fever vaccine. Dr. Steven Webster (Dean Jagger) meets both Jenny and the dog and "adopts" them both. His fiancee Susan (Ruth Warrick) isn t too fond of either the girl or the dog. Webster wants to get a hospital for the town but he is suppressed by the town mayor (Jerome Cowan.) In the arguments that follow, Webster s lab is wrecked and ticks infected with spotted fever escape. The town is in a panic and all want to be vaccinated. Jenny is infected and is about to die.