Illegal puppy trading across Europe generates an estimated one billion euros a year, on par with trafficking in drugs or weapons, according to the animal welfare group Four Paws. The film follows investigator Birgitt Thiesmann, a former reporter for the German magazine Bravo who now spends her time tracking down the networks behind it. She meets animal sanctuaries, police, vets, and buyers left with sick or dying dogs, and describes being physically attacked and threatened for her work. In Prague she interviews a former "multiplier", the industry euphemism for a puppy mill operator, who quit the business and tips her off to an undiscovered breeding operation nearby. The camera follows her posing as a buyer to catch traders in the act, feeding information to vets and police who then confiscate animals. Overcrowded shelters in Germany and behaviorally damaged dogs in Belgian kennels show the trade's aftermath. The film stays close to Thiesmann's methods rather than statistics, tracking one investigator's small, hard-won wins against a continent-wide criminal trade.