Marshall and Lily need money to fix their apartment's crooked floor. Meanwhile, Barney and Abby go to the bar to flaunt their relationship in Ted's face.
Robin's musical past emerges again as the group learns of someone named Simon from Robin's past. As Barney searches for more Robin Sparkles memorabilia, Ted spends more time with Stella.
Barney's efforts to hook up with women are being thwarted by a mysterious woman from his past. Barney and the gang must sift though his many past flings in an attempt to find out who she is.
Ted lives like there's no tomorrow during a St. Patrick's Day celebration with Barney. Lily and Marshall spend the evening at their new apartment with Robin.
Ted's upcoming date with his doctor leads the gang to give him their own examples of why dating someone you already see regularly is a bad idea. Marshall and Lily want a couple to be friends with. Barney's last venture endangers the group's hangout.
When Barney loses his way with women, he hopes a trip to the Victoria's Secret Fall Fashion Show will help him regain his form. Marshall deals with a taskmaster of a trainer at a gym.
As Marshall and Lily prepare to host their first Thanksgiving as husband and wife, Barney eyes Marshall's Slap Bet Countdown Clock website with dread. Marshall has a gift for everyone.
Marshall has to contemplate giving up his plan of using his law degree to help the planet when he's courted by a major firm; Lily reveals a secret to Robin that not even Marshall knows; Ted discovers a porn actor is using his name
Amid sharing stories with her about how members of the gang met each other, Ted's hot new girlfriend has a reaction to the meeting that gets her a high ranking on Barney's crazy scale.
Ted's new attitude attracts women in the present and one from his past. The rest of the gang pulls together to help him make the most of the situation.
Ted and Barney pretend to be visitors to New York City to pick up women. Robin is still dating Gael. Marshall and Lily prepare letters to each other to be read after their death.
We pick up from last year. Robin shows up with a date and this motivates Ted to 'get back out there'. We also learn/learned something major about 'the Mother'.