On tonight’s Big Bang Theory, Amy brings up a new intimacy test that supposedly makes people fall in love with each other in two hours. Participants ask each other questions to promote intimacy and then stare in each other’s eyes for four minutes. Sheldon decides he wants to test this, so Penny agrees to help.
Sheldon follows Penny to her apartment to start the experiment, meanwhile Raj doesn’t see why Amy and Leonard are okay with it. They both think that it will be okay. Amy and Leonard decide to do it with each other, but it doesn’t get past the first question due to Amy’s disgust of Leonard’s cheesy answer.
Instead, Leonard, Amy, Emily and Raj decide to go to an interactive theatre where they are trapped in a room with a zombie and have to solve puzzles to get out. The gang is underwhelmed by the experience because they figure out the clues in six minutes.
Back at the apartment, Sheldon and Penny start answering the questions that consist of things like their idea of a perfect date and qualities they wish they possessed. Sheldon also tells Penny that today is his birthday, which is something he has never told anyone. To complete the test, they start to stareinto each other's eyes, but they both find it creepy. They break the stare and start to talk about how they see each other as brother and sister. They share a nice moment when Penny starts reminiscing about when they first met. That is until Sheldon points out that she still eats their food and he remembers how much she owes them for it. After the four minutes, they agree that they are not in love with each other.
Penny walks Sheldon back to his apartment. When he walks in, the apartment is decorated and gang jumps out and yells surprise. Sheldon becomes disappointed that Penny told them it was his birthday.
In tonight’s subplot, Howard finds that his mom’s ashes were lost by the airlines. They believe that someone may have taken the bag off the carousel. While waiting, Howard reminisces and feels guilty for not driving her to the airport because he was “too busy.” Seeing Howard sad, Bernadette goes over to the airport employee and threatens her saying that one way or another they will be leaving there with a dead woman.
The woman manages to find the luggage with the urn in it. Howard starts talking to his mom’s ashes and Bernadette realizes that the urn is going to end up in their bedroom.