It's 1940 and Nazi bombs are raining down on London, but 13-year-old bike messenger Jack has just discovered something unbelievable: a stray dog with a surprising talent.

Jack navigates the smoky, ash-covered streets of London amid air raid sirens and falling bombs, dodging shrapnel and listening for cries for help, as a bike messenger for fire crews. When Jack finds a dog, miraculously still alive after the latest Nazi bombing of London, he realizes there's something extra special about the shaggy pup--he can smell people who are trapped under debris.

With his new canine companion, nicknamed Rip because of the dog's torn ear, maybe Jack can do more than just relay messages back-and-forth--he can actually save lives. And if Jack's friend Paula is right about the impending Nazi invasion, he and Rip will need to do all they can to help Jewish families like hers.

There's just one problem: Jack has to convince his ill-tempered father to let him keep Rip.

Based on true episodes during the London Blitz in World War II, this action-packed and touching story explores the beginnings of search-and-rescue dogs and the bravery and resourcefulness of young people determined to do their part for their country.