As a puppy, Stella was trained to use her powerful beagle nose to sniff out dangerous chemicals and help her handler keep people safe. During a routine security inspection, Stella misses the scent of an explosive. The sound of the blast is loud and scary. Unable to go back to work because of her anxiety, Stella is retired as a working dog. A young girl named Cloe wants to adopt Stella, the beagle smells a strange chemical inside Cloe's body, a scent that surges just before the girl has a seizure. Stella's nose makes the connection, but how can Stella warn her new family?