Plot (Spoiler)

Stewie shows Brian a remote control that allows him to access parallel universes depicting Quahog in the same time and place, but under different conditions. Travelling to a universe where humans are subservient to dogs, Stewie is unable to figure out how to modify the device so that they can return home. Brian is reluctant to leave and forcefully swipes the remote, accidentally breaking it. The two head to the universe’s Griffin family, who are all dogs, except for their pet Brian, who is human. The dog version of Stewie explains that he has developed his own remote control. While he goes to fetch it, human Stewie bites the dog version of Peter and is sent to the human pound, where he will be euthanized. Human Brian, regular Brian, and dog Stewie go to the pound, free Stewie, and both regular Stewie and regular Brian are sent back to their universe.