Leonard tells Zack and Marissa he will father their child, but Penny tries to seduce him despite knowing he has to be abstinent for a few days. Her visiting father, Wyatt, points out her actions suggest she is more conflicted over having kids than she lets on, which she admits. Wyatt says he will support her no matter what. Meanwhile, Sheldon and Amy warn that he will not be allowed to raise a child that is not his. Leonard decides not to go through with it; he tells Zack to have Sheldon be the donor, but Amy forbids it. Meanwhile, Howard turns Raj's cancelled bachelor party into a couples' trip into a zero-gravity aircraft, though he's convinced that Bernadette would hate it. Bernadette tries to get out of it so Howard sits out, forcing Bernadette to go through with it just to prove him wrong, though she does not enjoy it.
After Sheldon reminds the guys about the time they mined Bitcoin without him, the guys go on a quest to find their suddenly valuable missing cryptocurrency. They realize the currency is on a laptop which Leonard gave to Penny when they dating, which she then gave to her ex-boyfriend Zack. After Leonard and Penny go to Zack's apartment, he shows them a seven-year-old video that Penny recorded on the laptop soon after she broke up with Leonard. Leonard is touched by the video which shows a drunk Penny lamenting the break-up of her relationship with him.