How I Met Your Mother

Season 6 Episode 11

The Mermaid Theory

Aired Monday 8:00 PM Dec 06, 2010 on CBS
out of 10
User Rating
302 votes

By Users

Episode Summary

As Ted and Zoey test whether a guy and a married woman can be friends, he tries to befriend her husband as well. Marshall and Robin try hanging out alone. Barney and Lily have a spat.

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  • "I'm Sorry for Wasting Your Time"

    Oh, wow. This episode is totally confusing and makes very little sense at all. Not only that, but the "plots" that it "furthers" are tedious and full of plotholes. But I'll give this a shot. So, Ted's invited to go to a boring architecture thing with Zoey and everyone else makes up an excuse not to go, leaving Ted and Zoey alone. Lily lays out the rules to him of how he can behave with Zoey, as a single male friend. Basically, they can't lie about anything, no candles, and nothing involving saliva. Something like that, but I'll clarify in the weecap. Ted goes, and there is a small lie: Zoey tells the Captain she's with Then she invites Ted to hang out with both of them to make up for it, but no-shows. Ted spends the rest of the episode on the Captain's boat, afraid the crazy man is going to kill him. In the end, Ted and Zoey are alone together again, and sparks are beginning to fly. This is our plot development, but we get Saget!Ted's kids and his narration a lot this episode, which just made it obvious that Zoey can't be the mother. If she were, wouldn't Saget!Ted not keep calling her "Zoey" as his kids stare at him blankly?

    Elsewhere is the confusing storyline in which Barney and Lily get in a fight. The reason it's so confusing is that Saget!Ted can't remember who is mad at whom, or for what, or when. He ultimately remembers that the fight he's connecting to the rest of the episode actually took place a year later, when Lily is pregnant, so we get a little flash-forward that includes Ted in a green dress. While Lily and Barney fight, Marshall and Robin try to hang out alone and test the Mermaid Theory of the episode's title: It's Barney's theory that if you are around any woman long enough, she will go from being a manatee to a mermaid. That's why Marshall's never hung out alone with Robin: He needs her to remain a big, fat manatee. There's awkward conversation, but then he fills her in, then they drink. Just as she's morphing into a mermaid and he's panicking, she vomits and gets disgusting and manatee-like again. Phew.

    Oh, and the Barney-Lily and Marshall-Robin storylines do connect, because the fight Barney and Lily are having ends up being about the Mermaid Theory. Because the only antidote to mermaidism is pregnancy, which is why Barney no longer finds Lily attractive, and why she gets mad and cries that he'd call her a "big, fat He promises her she'll get hot again just as soon as she starts breast-feeding, because (insert boob- and penis-swelling joke).moreless
  • A Mermaid episode

    Now that Zoey is part of the group, things have changed for everyone. Ted agrees to hang out with her (without the captain) at an Art Museum. He makes it clear to his friends that this is not a date even some think that he is. Things get complicated for Ted when he realizes that Zoey lies to the captain about who she is hanging out with. When Ted tells what happens to his friends, this brings another theory by Barney. While there is some truth in it. I do have a problem with it. It's not much the theory but how Marshall believes in it. Yes people even friends of the opposite sex can be attractive (especially with alcohol) but Marshall worried about Robin becoming a mermaid shouldn't be an issue. He is fully committed to Lilly. Also Robin and Marshall have hung together alone since Marshall got married. What Robin said about a single person and a married person hanging out together, I completely agree with. Marshall and Lilly's time together was a bit like when Marshall and Lilly hung out with Robin and Barney in season 5. It was only slightly less weird. I don't like how alcohol brought them together for this episode.

    The best part of this episode was Lilly and Barney hanging out together. Future Ted getting things mixed up reminds you that one it's funny and two, Lilly is successful in getting pregnant. It also got you interested in why Ted is in a dress. And yes you find out why. But I won't tell you when.

    On a small note I think the captain was good in this episode. Not many people can switch between scary and nice as effectively as he can. At the end when you hear the clock when Ted and Zoey are in the bar, I think that happened a lot sooner.moreless
  • Marshall and Robin have an awkward dinner.

    "The Mermaid Theory" is a great How I Met Your Mother episode. I loved Ted's plot in this episode. It was funny. The Captain was really creepy with inviting Ted on his boat but it was funny how Ted thought The Captain was going to murder him. I love how Future Ted got the Barney/Lily story mixed up because it actually shows his age. I love how Lily actually is pregnant in the future and I really want to see why Ted was wearing a dress. The Mermaid Theory was entertaining when Marshall has to explain it to Robin during their awkward dinner. I know it's weird, but I kind of wish Marshall viewed Robin as a mermaid instead of a manatee. I give this episode a 9/10.

  • the first joke about the jonas brothers is kinda lame... but..

    the first joke about the jonas brothers is kinda lame... but.. overall the episode was superb... don't get me wrong, i'm not a fan of the jonas brothers but that joke made me think if i wanna watch this episode because of that opener joke? so i let it go, and see the entire episode and i may say its on the top episode this season. and zoey is hot.. buut Cobie Smulders is getting matured physically... why is that? is she stressed? and miss Alyson Hannigan also getting dull.. they must show more skin so they can be more interesting to look at.. about the jokes, we can see that there is an effort in coming up with those punch lines and situations.. but the opener, poster of the captain, jokes are all lame... ok, my word count is 140+ now so i will end this by saying zoey is hot!!!moreless
  • Classic HIMYM

    This was a classic How I Met Your Mother episode like the ones we were used to in the first few seasons.

    There was (finally) a theory again, one of the features that make this show so epic in the first place. Things like the olive theory, slapsgiving, the bro code et cetera. I really miss these elements.

    I also really enjoy the twists and turns that change and evolve according to the storyteller's memory, like in this episode, when the background of the fight between barney and lilly is slowly but surely revealed.

    Finally, the intelligently humorous scene with ted and the captain definitely stole the show, rivalled only by the closing scene with barney and marshall as pirates. All in all, a great episode.moreless
Tamara Lynn Davis

Tamara Lynn Davis


Guest Star

Angus McClelland

Angus McClelland


Guest Star

Bob Saget

Bob Saget

Voice of Ted, 2030

Recurring Role

Jennifer Morrison

Jennifer Morrison

Zoey Pierson

Recurring Role

Kyle MacLachlan

Kyle MacLachlan

George "The Captain" Van Smoot

Recurring Role

Featured Episode Clip

Trivia, Notes, Quotes and Allusions


  • TRIVIA (1)

    • Marshall told Robin that they never hang out together and today's dinner is the first time when there is just two of them. This is not true, because in "Little Minnesota" Marshall took Robin to his favourite pub with a Minnesota theme and then to Hoser Hut, a Canadian bar.

  • QUOTES (7)

    • Marshall: Captain, what do you think of ice cream? (Covers the top half of the poster of the Captain's face) Oh, he loves ice cream!
      Barney: Captain, what do you think of rainy days?
      Marshall: (Covers the top half of the Captain's face) Oh, he hates em!
      Robin: Captain, question. How do you feel about the Jonas Brothers? (Marshall covers a vertical half of the Captain's face)
      Ted: What is that?
      Marshall: He hates that he loves them.

    • Lily: Rule number one: Don't go anywhere that has candles.
      Marshall: Excuse me captain, how do you feel about Ted and Zoey having an intimate chat by candlelight? (Covers the bottom half of the Captain's face) It'll be the last dinner they ever have.

    • Lily: [Zoey] lied to her husband?
      Barney: Please, you lie to her your husband all the time. (imitating Lily) "That's a great shirt." "I love your mom." "I don't secretly fantasize about Barney while we're doing it." Sound familiar, Pinocchio?
      Marshall: What's wrong with this shirt?

    • Lily: Rule number two: no sharing food. In fact, anything involving saliva is off limits: toothbrushes, thermometers, lipstick.
      Ted: Well, if I can't share her lipstick there's really no point in even going.

    • Lily: Anytime a single guy hangs out with a married woman there are rules that must be followed. Rule number one—
      Barney: Don't use the husband's condoms. That's just rude.

    • Marshall: (on The Captain) That man is terrifying.
      Barney: Everything he said was nice, but I'm profoundly scared.
      Ted: Keep smiling, he can still see us!

    • Ted: Hey, guys, Zoey just told me about this great Frank Lloyd Wright retrospective. Who's in?
      Lily: Sorry, I'm, ummmm, I don't know, washing my hair.
      Marshall: Running the water.
      Robin: Holding the towel.
      Barney: I'll be home trying to get over the fact that no one invited me to the big hair washing party.

  • NOTES (1)

    • International Airdates: Australia: March 10, 2011 on Channel 7; United Kingdom: May 12, 2011 on E4; Germany: October 12, 2011 on ProSieben; Czech Republic: January 31, 2012 on Prima COOL


    • When Barney says that a women, when she becomes pregnant, heads straight back to Manatee City, where the grass ain't green and the girls ain't pretty, he was playing on the lyrics of the song "Paradise City" by Guns N' Roses.