Spoilers for the next 3 eps.
Source: SpoilerFix
11/28 - Episode 1.12 - The Wedding: Ted plans to bring Robin as his date to a wedding but the bride says he did not RSVP with a guest. When he goes around her and gets permission from the groom, Stuart, he causes a fight between the couple and he calls off the wedding. Ted's fantasy with Robin is jeopardized unless he finds a way to get them back together.
12/11 - Episode 1.13 - Drum Roll Please: Not having Robin at the wedding, Ted is pretty bummed until he meets Victoria. They hit it off but don't want to get caught up in the moment so they make a deal. They will live this night for the moment, exchange only first names, and never see each other again. When Ted tells the gang the story, he realizes he has to see her again and gets Barney to help him find her. Robin knows who she is but will her own feelings get in Ted's way?
12/21 - Episode 1.14 - Marshall-opoly: As Barney shares his most embarrassing moment with the gang we see flashbacks of what he was like before he started wearing suits all the time and sleeping around, and learn what caused him to change. Ted, Marshall, Lily, Robin and Victoria also appear.
Source: SpoilerFix