Is there a single person out there who watched Lily leave that drugstore and didn't immediately thing she was pregnant? No, right? That was just oblivious William Zabka and the rest of the slow on the up-take gang, right?
We pick up tonight seeing that Robin's mom is Tracey Ullman and find out she had to be restrained with duct tape in order to fly the not-so-friendly skies (she's taking a train home, and maybe she'll meet the Mother before Ted does). Anyway, she can't wait to meet Barney (who is waylaid by a saltine-eating contest) and goes on about all of the terrible things that she hated about Robin's dad. And most of them are things that Barney has done, up to and including getting engaged to a stripper. Lily tries to call in the fellas for some reinforcements because Robin (who is still wearing her hockey jersey a few hours before her wedding, even though didn't they go take pictures?) is on the verge of a meltdown.
But aside from the saltine festivities, the fellas are all brunching and talking about how Lily stormed out of the hotel for a few hours and then came back in a much better mood. William Zabka conveniently was out and saw her leaving a convenience store in a car with an "Ahoy!!!" license plate. They slowly jump to the conclusion that Lily went to have sex with The Captain, a.k.a her boss. And that doesn't even make a tiny bit of sense, given what we know about Lily. Wouldn't you presume that after finding out her husband wanted to stay in New York that perhaps she was going to see her boss to discuss the possibility of working remotely instead of in Italy, or maybe a part-time trip to Italy? Something like that?
The moronic boys decide to drive to The Captain's Hampton house which is conveniently close, even though everything in the Hamptons seems really far from each other in actuality. Marshall slugs The Captain straight in the face before he has a chance to offer up an explanation. It turns out there was no affair (of course) and that he's happily hooking up with Boats, Boats, Boats. But Lily did show up at their house in the middle of the night and hid in the bathroom for a while before she left.
Ted uses his deductive reasoning skills to realize there is a potted plant (an extremely fake-looking daisy, to be specific) in the bathroom, which is where Lily hid her cigarette butt. His false presumption is that the reason she was so agitated was because she picked up smoking while Marshall was visiting his family, and was jonesing for a fix, which explains some random gum-chewing she did and why she wanted to be on the train. Instead, we find out that the daisy has a pregnancy test in it, which would be a pretty crappy thing for the very peppy singing household staff to have to find.
The test, of course, is positive (and don't worry, Linus has been giving her mock-tails all weekend... which seems questionable but I just don't care anymore), and Marshall rushes back to the hotel to see his wife. He immediately tells her they are going to Italy after all because his dream was just to have another baby so he's really thrilled. She has a hunch that the baby is a girl, and Marshall idiotically asks if she knows that for sure... Dude has had a baby before; he has to know you don't find that you when you JUST peed on a stick. I hate when they make these supposedly smart characters really dumb.
While they celebrate the baby -- with some baby making -- in Robin & Barney's hotel room, Robin's mom meets Barney for all of about four seconds and deems him nothing like Mr. Sherbatsky and then they hide out on the balcony until the Eriksens are finished with their business.
We see a year into the future that Marshall and Lily are living in Italy and fighting over Funyuns, with her father Mickey, toddler Marvin and baby Daisy. I can't believe they named the kid after the plant she stuck her pregnancy test in. That'll be a great story to tell their kids someday.