Mrs. Pynchon's dog Barney disappears while she goes shopping. Billie checks the dog pounds, an advertisement in the paper asks for witnesses. A man did see a suspicious pick-up with a lot of dogs in a cage. As he noticed the unusual license plate (KONG 12), Rossi and a policeman find the house of the pick-up's owner. They find strange training apparatus and dog leads in the yard. (Unfortunately their search is completely illegal.) Barney's lead is among the items found. Rossi checks with Jim Lawrence of the Humane Society. Lawrence explains that the things found in the yard suggest that pit bulls were being trained to fight. Mrs. Pynchon's little terrier was probably used to get the dog accustomed to the kill.
Lou and Rossi bring the bad news to Mrs. Pynchon. Her sad reaction prompts Lou to give Rossi the permission to go and investigate dogfights. With Jim Lawrence Rossi visits a dog show, because people who organize dogfights, also show up there to get legal credibility. Rossi talks to some people with dangerous dogs, but can't find information about fights. The only way to learn more about the fights, is to go undercover. Lawrence is known to the bad guys, so Rossi takes the assignment. He gets a job at a gas station dog fighters are known to frequent. He starts up a conversation with a customer with a pit bull, pretending to have been involved in fights himself. The man invites him over to look at his dog at home.
Meanwhile the people at the Trib have bought a little dog for Mrs. Pynchon. She cannot accept it, however, as she is still hurting from the loss of Barney. Now Lou is stuck with the dog. He unsuccessfully tries to give it away to Billie and other reporters.
At the home of the dog fighter Rossi witnesses a pit bull training: a cat is put in a bag and killed in thirty seconds. Rossi can keep his cool and so the men invite him to a real fight. The exact location will only be known on the day.
Rossi gets wired for sound and leaves with the men to the fight. There he gets recognized by the men he talked to at the dog show. They start to beat him up when the police arrive. Jim Lawrence shows his appreciation for Rossi's work by giving him a Humane Society t-shirt. He mentions that the arrested men will only get a 50 dollar fine. If Rossi writes a good article about it and more people get aware of the problem, that might change in the future. Mrs. Pynchon shows up at Lou's house. She's changed her mind and will accept the pup.