Stella's sister Nora is a hottie. She's also a judgmental vegan who rubs Ted the wrong way on a good day. When she sets her wedding date prior to Stella and Ted's, and co-opts every single wedding idea Stella has dreamt of since she was a girl, Ted gets all competitive. He wants his wedding to Stella to completely outshine Nora's. Stella goes Ted one better and gets vindictive. She wishes Nora's relationship would fall apart before the couple makes it down the aisle, and that's what happens. Stella is magic! She and Barney could take their act on the road.

Nora is bitter, eating meat like she's a jungle cat, and ranting that she's about to be out thousands, because it's too late to get refunds. Ted and Stella have one of those telepathic conversations couples can sometimes carry off. They agree they should help her. The problem is their definition of help. To Ted, it means they'll pick up that night's dinner tab. To Stella, it means they'll take over Nora's plans, marry each other three days hence, and reimburse Nora for all expenses. Ted's hesitant at first, but Stella woos him with her talk of spontaneity and criticism of Lucy's dad, Tony, for lack of same. He promised for years to marry her, but never quite got ready. You'll find that won't be a problem with Ted, Stella.

Saget!Ted tells his kids to never invite their exes to their weddings, and then we see current-day Ted doing just that. It's Robin's first week on the job as the anchor of the number 1 English language newscast in Japan, but the job makes her old slot at Metro News 1 look dignified, so Robin agrees to attend and books her flight home. Lily, Marshall and Barney are miserable, because Nora booked the wedding at the Namaste Yoga Collective, which has a vegan menu and a strict no-alcohol policy. Stella really freaks about Robin coming, because Robin is Ted's ex. What if having an ex around brings up unresolved feelings? The only person more unwelcome in Stella's eyes is her own ex, Tony. Stella begs Ted to rescind Robin's invite. He foolishly takes Barney up on his offer to make the awkward call. Barney's only willing to do the dirty work, so that it won't get done. He plans to take advantage of a vulnerable Robin at Ted's nuptials, and won't let a little thing like honor get in his way, which is why we love him so. His only problem, aside from the fact that there will be no alcohol at the wedding to make Robin a bit more pliable, is that Nora is determined to get him in bed to help her forget this is supposed to be her wedding, and he's having trouble resisting, because she's incredibly hot, and even more forward, and he's Barney.

Barney lies to Ted that he didn't reach Robin, so Lily advises Ted to solve another crisis for Stella, and then break the news to her that Robin will be there. Sure enough, Tony has Lucy that weekend and won't let her come to the wedding, so Ted goes back to get her. Tony is emotional and feels left out and like he's losing his family, so Ted brings him back to Shelter Island to attend the wedding. When Stella sees him, she lashes out at Ted and things do not get better when Robin is the next person she sees. Stella and Ted go off to talk alone. She can't bear the thought of their exes being at her wedding and that's that. She says she'll talk to Robin, asks Ted to talk to Tony, because she can't handle him right now. She wants them both gone. Ted sees this wedding won't come off with their exes there, so he agrees, but insists upon talking to Robin himself, because she came so far for his sake. He leaves the Tony problem to Stella's capable hands. Ahem.

Robin's actually relieved to have the invitation rescinded. She feels horrible being the ex at Ted's wedding, and always thought maybe they'd have another chance if her feelings on marriage and children changed. Ted thanks her for making him her safety school, and no kidding. Way to get him back, Robin. She goes on to tell Ted that he's an incredibly romantic man who has somehow fallen into someone else's story -- someone else's wedding – someone else's home – someone else's life, and is in danger of disappearing altogether, when his happy ending should be as incredible as he is. That's better, girl. Ted only took offense to the idea that he's jumping into this marriage because he's jumping into this marriage. He tells Robin he'll be marrying Stella and if she feels the way she does about his decision, it's just as well that she doesn't attend.

Robin goes to Barney's room for some ego boosting, but he's already got a woman in his bed, and can't manage to hide that from Robin, despite a truly valiant effort. Robin leaves. She's quit her job to come home to her life. We watch her looking dejected as she rides the ferry back to New York. Cut to Ted in his cabin at Namaste, reading what appears to be a Dear John letter. Cut back to a miserable Robin, sitting on a bench on the ferry deck. She sees Stella -- in her gown -- standing at the rail. Cut back to Ted's friends joining him one by one, and solemnly reading the note. Cut back to Robin, watching Stella, who is joined by… Tony. I know you're shocked. I'll give you a moment. Moment over. Ted's marriage fixation blinded him to the real root of Stella's objections to having exes at their wedding. She isn't over hers. Robin looks on in horror as Stella and Tony kiss, and Saget!Ted warns, "Seriously kids, never invite an ex to your wedding." Oh I don't know, Saget!Ted -- thanks to the exes this wedding turned out way better than I'd hoped.

Check back on Wednesday for the full recaplet. Until then see our favorite HIMYM lingo.