Allie and her partner Duncan set out to find a canine friend for their simple dog. At the shelter, workers warn them that a German shepherd mix has significant issues, but they decide to adopt her anyway. The new dog, whom they refer to as the helper dog in the hopes that this dog might help their other dog understand the world a bit better, does not seem interested in human interaction. However, when they introduce the two dogs, the helper dog turns out to be dog-aggressive to any dog within sight.

Allie and Duncan try everything they can think of in terms of training and classes to improve the behavior of the helper dog, but nothing they try works.

Allie attempts to train the new dog by giving her a treat every time she stops being dog-aggressive, but instead this trains her to briefly be dog-aggressive, stop for a treat, and go back to being dog-aggressive. She also teaches the simple dog to be dog-aggressive.

At night, the helper dog waits for a neighbor to bring their dog out for a potty break; when the other dog emerges, the helper dog tries desperately to get outside to attack the neighbor’s dog by slamming her body against the glass sliding doors.