Plot

Amy's desire to have an intimate night with Sheldon on her birthday is interrupted by Bernadette going into labor.

It's around midnight. Bernadette has gone into labor, with Howard, Raj and Stuart rushing her to the hospital. News of the labor makes its way back to their friends. It's the start of Amy's birthday, the news of the labor which interrupts Sheldon's annual gift of birthday coitus. Beyond Amy looking forward to this annual event, other items beyond the labor may make it more difficult for both Sheldon and Amy to get back into the mood. A baby coming into the world and the fact of Amy's birthday gift lead to Leonard and Penny thinking they too should have sex, which is dependent upon Leonard being able to find some things, including his breath. And in the process of the evening, Raj does something which may place him in Howard and Bernadette's bad books for the evening if not longer. Raj, feeling depressed about putting nine months into being there for Howard and Bernadette and potentially missing the birth, leads to he being shuttled between friends, who may or may not want to help him get out of his funk.—Huggo

Bernadette, Howard, Raj and Stuart are heading to the hospital while Bernadette has another contraction. Raj wants to drive like he's in India..

Sheldon wakes up Amy just after midnight to wish her a "Happy Birthday". Amy is touched until Sheldon blows a birthday horn in her face. Sheldon hands her his birthday present and opens it up; a framed functional MRI scan of his brain. She loves it. Sheldon points to the bright spot orbital-frontal cortex where he was thinking of her. Amy kisses him and then Sheldon asks if they are starting their annual coitus birthday festivities in the evening. Sheldon moves in on her while wearing his come-hither pajama bottoms. Penny knocks on the door announcing that Bernadette was heading to the hospital.

Bernadette, Howard, Raj and Stuart make it to the hospital. Althea the nurse makes cracks asking about the three guys and one expectant mother whether this was some "Mamma Mia" nonsense. No Howard is the father though he doesn't know how far apart her contractions are. Raj does. Twelve minutes. The nurse wonders why they came so early. Althea sends them home until the contractions are five minutes apart for about an hour.

Sheldon, Amy, Leonard and Penny are heading down the steps. Sheldon didn't want to look foolish if Howard started handing out cigars, so he had to find his bubble gum cigar. Leonard then forgot his inhaler. Penny gets a call that it's a false alarm. Amy wants to head back to their apartment, while Penny suggests that they go to a diner. Sheldon tells Amy that since its her birthday, she should decide. Now Penny gets excited and says that they should head to a bar. No. Leonard then states that they want to go have sex. Penny calls it their annual birthday booty spectacular as she sends them off to have fun.

Back in their kitchen, Raj is filming a nervous set of soon-to-be-parents. Howard tells him to turn it off, while Raj is doing it for the baby. He says that someday she is going to see the film. Oops. Bernadette and Howard are disappointed that Raj let it slip that they are having a girl.

Back in Shamy's bedroom, Amy asks: Where were they?. Sheldon described it as kissing like randy teenagers and that Amy's nose whistles. They try again and Sheldon thinks that it was being forced like all the "Pirates of the Caribbean" sequels. Sheldon still wants to continue since Leonard and Penny are probably engaging and he doesn't want to disappoint them.

Leonard comes out with his spare inhaler and ask Penny if they want to have sex. As they start to kiss, Raj knocks on the door. Raj got thrown out for telling them that the baby is a girl. Oops, he did it again. Penny asks that if they are quiet, he might go away. Raj heard that.

In Sheldon and Amy's apartment, Sheldon has his eyes closed as Amy comes out in a Harry Potter robe posing in the doorway. Sheldon is impressed, Wowzers! She goes back to get him his robe. Sheldon calls her a naughty girl because wizards from different dorms will be sleeping together. Then he is a bit annoyed that she went to a Harry Potter Wizarding World theme park without him. There's a knock at the door. Amy sticks her head out the door and asks if this intrusion was about the baby. Raj replies that people keep kicking him out of places. Then Penny and Leonard run out of 4A out yelling that they are all heading toward the hospital because Bernadette's water broke. Amy shouts that they have got to be kidding.

Howard and Bernadette head to the hospital with Stuart at the wheel. Howard thinks that Stuart is driving like an old man, while Stuart says that he can't see during night time.

Sheldon, Amy, Leonard, Penny, and Raj are in the car heading there themselves. Penny says that it's cool that the baby will be born on Amy's birthday. She complains that she thought the baby was supposed to ruin their sex life and not hers. They end up discussing the interruptions of the their sex lives and how long it took. Raj adds that they threw him out and let Stuart stay. Sheldon points out that he just discovered Amy went to a Harry Potter theme park without him, but he's not going to ruin her birthday because of that.

Howard helps Bernadette through another contraction. She wants some ice chips; however, Stuart finished them. Howard and Bernadette discuss names. Howard wanted Wally Wolowitz if it was a boy. Bernadette suggests naming her after his mother Debbie, but she hates that name. Her middle name? Melvina. Howard really missed her and thinks that she would have been a great grandma.

The gang is waiting while Leonard cannot believe that Howard was going to be a father. Amy adds that Penny is the one who introduced Bernadette to Howard. Then they all consider how far they have come since Penny moved in and that they all have a lot to be proud of. Raj gets mad that they all think he has done nothing. Stuart tries to console him and then Raj complains that he is as awesome as a pasty-faced comic book store owner.

Howard is now walking Bernadette around and telling her to remember what she learned in birthing class. Yelling she complains that she thought it was stupid and she was right.

Raj returns to the waiting room. Penny starts to tell Raj all the things he has accomplished like now being able to talk to females. Stuart tells him that at least he can be a dog owner. Howard comes in and announces the birth of their daughter, Halley, named after Halley's comet. Also like the comet, Bernadette is not having sex with him again for 75 years. Howard can't wait because they are all so happy for Halley to meet her aunts and uncles and Godfather (Raj). Raj is ecstatic that he has a dog and a godchild.

Peeking into the baby nursery, they see all the new individuals. They all wonder which one Halley is. All the babies look the same to Amy. Raj is sure he knows since it's his goddaughter. Then they hear one that cries like Debbie Wolowitz, and are stunned, as Raj remarks, "That one."

Amy and Sheldon are returning from the Wizarding World Of Harry Potter dressed appropriately having had a fun day. Amy thinks that he would be tired. Sheldon replies, "I saw a magical train and reported a guy for cutting in line. If that's not foreplay. I don't know what it is." They both race into their apartment for a romantic evening.

Title reference: Halley Wolowitz is born on the same day as Amy's birthday.