Peter got an "Alexa" and introduces it to the family. Brian goes off about people and technology.
Brian starts talking to "Alexa" and becomes addicted to her.
Stewie creates a machine to get into Brian's body so he can fix his loser self. They're going to swap bodies. Using the machine is successful.
Stewie gets Brian a job as an English professor. He's going to change Brian's life.
While Stewie works to switch back to his body, Chris and Peter fight and roll into the machine and now Peter is Stewie, Chris is Brian, Stewie is Peter and Brian is Chris.
Stewie tries to switch everyone back, but the machine is broken.
Everything is going haywire.
Chris gets into a car accident turning the machine on and the whole town has swapped bodies.
It's a Freaky Friday.
Peter and Lois are on a sex trip. Stewie is completely freaked out. He calls Brian to fix the machine while Lois is trying to get frisky with him.
Brian is successful in getting the bodies swapped back, he thinks but it doesn't work. Brian is in Peter's body and ends up having sex with Lois.