|Hippie, Hippie, Hooray|
|Season 4, Episode 21|
|Air date||February 1, 1968|
|Written by||Michael Morris|
|Directed by||William Asher|
If They Never Met
A Prince of a Guy
Early in the morning, Samantha discovers something on the first page of the newspaper, an article of a "Love-in Riot", with a picture of Serena looking like her. Before Darrin sees the paper, Samantha use her powers to erase the photo, which cause Darrin a bit of confusion as to why there is no photo.
At the Tate's house, Larry sees the photo in the newspaper and believes that Samantha had gone full hippie with Darrin keeping it a secret. At the office, Larry invites himself and Louise to come to the Stephens' house that night for a game of bridge. At the Stephens' house, as Sam and Darrin are preparing to play bridge, they hear music upstairs in Tabitha's room, only to discover that it is Serena playing the music as a lullaby for Tabitha. Darrin then realizes that the reason why Larry invited him and Louise to come to the house is because he thinks that Serena was Sam in the photo that Sam erased. After an argument, Darrin tells Serena she is not allowed to come to the house anymore.
After leaving, Serena overhears Darrin rant about what happened and she decides to get payback. As the Tates arrive, Larry admits that he was wrong about Sam being a hippie. Then he sees the guitar which Serena left, convincing him that Sam really was arrested. During the game, a news report shows Serena getting arrested and Darrin tries to point out that is Serena, Samantha's look-alike cousin.
The next day at the office, as Darrin and Larry are trying to get a account, Serena arrives (dressed like Sam) and acts differently, resulting in them losing the account. However Larry does not care about the account. He says he is worried about Sam's behavior. Darrin keeps telling him that it was not Sam, but her twin cousin. To prove it, he invites Larry and Louise to the house so they can finally see and end the confusion. Later, Sam attempts to call Serena to come, but she refuses to answer. Sam comes up with the idea to transform herself into Serena, and switch back and forth between herself and Serena to try to convince the Tates.
The Tates arrive. Sam as Serena sings a song to prove that she is Serena. Afterwards, Sam and Darrin realize that since dinner time is approaching, Larry and Louise will expect to see Sam and Serena together at the same time. With no other solution, Darrin apologizes to Serena for what he said about her. Dinner is ready and Larry asks where Serena is. They say she went upstairs because of a headache. Hearing Darrin's apology, Serena comes down and thanks Darrin for his apology.
- Agnes Moorehead did not appear and received credit only.
- Diane Murphy was not credited for playing Tabitha.
- The episode title is an allusion to the cheer, "Hip, hip, hooray!"