The episode begins and Barney is getting over his breakup with Quinn by celebrating "Bang-toberfest". He's at the bar and announcing his re-entry to the dating, banging world. Marshall gets to the bar and reports that Lily's dad, Mickey, showed up. Lily brings Marvin to the bar with Baby Marvin. Marshall takes Marvin and Lily tells Robin and Ted that they need a babysitter because Lily is about to go back to work. Her dad isn't an option. Robin volunteers saying that, she and Nick could babysit because they're really "clicking". Robin gloats that she's getting keys to her apartment made for Nick. Ted tells her he had some made for Victoria three weeks earlier.
Robin says Nick signed for a package when she wasn't home, but Ted wins by telling her that Victoria keeps tampons at his apartment. The next day, Lily and Marshall's nanny search yields "an angel sent from heaven." Her name is Mrs. Buckminster, but things turn not so angelic when she tells them her weekly salary. Ted reports to Robin that he and Victoria are RSVP'ing to a wedding in Jamaica that's in six months. Robin tells Ted she's heading to an island, too; Hawaii, where Nick's parents live. She asks Ted if he's met Victoria's parents, and he says he hasn't because they're dead. Robin doesn't buy it, and Ted admits they are not, in fact, dead. Finally, they found Julie Jorgensen from St. Cloud, Minn.
Marshall knows her dad, George Jorgensen, owner of George Jorgensen's Organs. Her brother, Morgan Jorgensen, joined the business and they now call it George & Morgan Jorgensen's Organs. She then mentions that they just opened another out of state, in Oregon. That one's called Piano Town. She's perfect and her salary seems reasonable. She has one more interview. That night, they call Julie and learn that the most amazing thing happened at her next interview. She met a single dad who's a billionaire and then next day they're going to head to Paris in his jet. Marshall, Lily and Marvin show up at Barney's place. Julie's there and Lily, is not pleased with Barney. Lily explains to Julie that everything Barney told her was a lie. She leaves and says she can't nanny for anyone whose friends with that monster.
She leaves, and Barney says he has interview in 15 minutes. He explains that Lily gave him the idea to save "Bang-toberfest" by interviewing nannies and posing as a rich, single dad. Lily yells at Barney. She tells Barney he's "the most immature person" she's met. At the bar, Robin gives Nick a prolonged kiss and Ted says she's overcompensating. Ted teases Robin about Nick's neediness, and Robin reminds Ted that Victoria is a total slob who throws things around the apartment. They both realize they're not too thrilled with their choices. Mrs. Buckminster shows up at Marshall and Lily's place, saying that a Mr. Stinson called the agency and offered to pay her salary. Mrs. Buckminster tells Lily to head off to work so she and Marvin can get acquainted.
Lily tries, but ultimately says she can't hand her baby off to a stranger. Lily apologizes and tells Mrs. Buckminster they've decided not to hire a nanny. Lily then tells Marvin she's going to hold him forever. Barney shows up at the bar battered and bruised, and recounts the story of how he was walking down the street and was suddenly surrounded by all the nannies he'd taken advantage of. He woke up in a dumpster, covered in diapers. Ted and Robin toast "to making these relationships last". But Old Ted says both relationships would end before the end of the month. Marshall and Lily wake up from a long nap, but freak out when they realize they don't know where Marvin is. Then, just as they walk into the living room, Mickey is walking back in with Marvin in the stroller.
He explains that he got home and Marshall was gone. "Mrs. Whatsherface" was gone, too. He saw Lily snoring and decided to lend a hand. He then recounts the rest of the day. He reminds Lily that when she was little he was a stay-at-home dad. She thought her grandparents took care of her, but he says it was him. He explains there are no picture of her after she started preschool because he had to find a way to fill the time with her gone and so he took up betting on horses. He says he'll be there for Marvin, if they want him to be, and Lily says he's hired.
Later, at the bar, Mrs. Buckminster is keeping an eye on Barney and making sure he doesn't advantage of women. The eventually end up in bed together. Mrs. Buckminster and Barney lie in shock, and Barney says, "This can never happen again". "Oh, pish-posh," she says. "You said that five times ago". The episode ends at this point.