Episode 21
Title: “Twin Beds”
Original Airdate: May 3, 2010

When Don asks Robin to move in with him, Barney and Ted realize that the relationship is getting serious, and they each decide they want to win Robin back. After getting drunk and making complete fools of themselves, Barney and Ted both apologize, but it’s too late: Robin moves out of her apartment with Ted and in with Don, and decides she needs time away from the group.

Marshall and Lily decide to get twin beds so they can sleep better, but revert to their old ways when they miss the intimacy.

Episode 22
Title: “Robots vs. Wrestlers”
Original Airdate: May 10, 2010

Barney scores tickets to an event featuring robots fighting wrestlers, but Robin holds her ground and refuses to join the gang at the event. Ted gets an invitation to a fancy party addressed to the former occupant of his apartment, and the gang decides to crash the party. Ted loves the highbrow party atmosphere, but everyone else feels out of place. Ted skips out on Robots vs. Wrestlers, and Barney freaks out that the gang is falling apart. But by the end of the night, both Ted and Robin return.

Episode 23
Title: “The Wedding Bride”
Original Airdate: May 17, 2010

Tony Grafanello, the guy Stella left Ted at the altar to be with, makes a movie all about Ted and Stella’s breakup, in which Ted is portrayed as the villain. Ted likes Royce, the new girl he’s dating, but he’s worried about what sort of baggage she might reveal.

When they see Tony’s movie, Ted realizes that he’s the one with baggage. He doesn’t want to tell Royce about his issues, but when he admits his past problems, she’s completely understanding—because she has way more problems, which leads Ted to dump her.

Episode 24
Title: “Doppelgangers”
Original Airdate: May 24, 2010

Lily and Marshall believe that seeing Barney’s doppelganger is a sign from the universe that they should start trying for a baby, but when it turns out that the doppelganger was really Barney himself in disguise, they start to have doubts. In the end, they decide to start trying because they are ready, not because of any cosmic signs. Robin gets an offer for a great job in Chicago, but turns it down so she can stay in New York and be with Don. When Don then gets the same offer and takes it, he and Robin break up.