The Big Bang Theory ended its 12-year run on Thursday night, and the show closed out with an hour-long series finale.
According to TVLine, in the first part of The Big Bang Theory finale Sheldon and Amy are eagerly waiting to find out if they won the Nobel Prize in physics. The pair are joined by best friends Penny and Leonard as they stay up all night waiting for the phone call.
Finally, the phone rings and Amy answers, staying cool and collected the entire time. When she hangs up she calmly tells her husband that they have achieved their lifelong goal of winning the Nobel Prize. The friends embrace and get emotional over the life-changing moment.
The next day, Sheldon and Amy are headed out to work when they're bombarded by press. Sheldon soon realizes that his life is about to change, and he doesn't like it. Later, when Amy returns home after getting a makeover from Raj, Sheldon gets upset again.
Sheldon storms out into the hallway of the apartment building just as the elevator door opens and Penny emerges, revealing that the elevator has been fixed, and is finally working after 12 long years.
Penny and Sheldon go out for drinks and talk about the situation. Penny decides to play a little drinking game, and ends up making Sheldon feel better about the situation.
The Big Bang Theory series finale Part 2 flashes forward two months later. Amy and Penny arrive home after getting fitted for the dresses that they plan to wear to the Nobel Prize ceremony in Sweden.
Amy reveals that Penny's dress had to be let out, and after she and Sheldon leave, Penny and Leonard reveal that they're expecting their first child together.
The couple joke that the baby is the result of Penny's night out drinking with Sheldon, and promise not to tell their friends until they've returned home from Sweden.
Meanwhile, Howard and Bernadette are getting ready to leave their children in order to attend the ceremony. Their kids, Halley and Michael are seen for the first time in the entire series. Halley has long blonde hair like her mom, and Michael has a mop of dark hair like his father. The kids are left behind with Stuart and his girlfriend Denise.
The gang head out, and during their long plane ride Sheldon can't help but notice Penny rushing to the bathroom. He gets worried that she may be sick and goes to talk to Leonard about it. Finally, the pair tell their friend that Penny is pregnant, but his reaction isn't what they expected.
Later at the hotel, Bernadette and Howard find out that their kids are not in very capable hands with Stuart. All the while, Leonard is furious with Sheldon for not congratulating him on the pregnancy.
Howard, Bernadette, Penny, and Leonard decide to go home and skip the ceremony. However, at the last minute they change their mind as they want to be there for their friends' big moment.Amy tells Sheldon that he's broken his friends' hearts. However, when he sees them all cheering from the audience at the ceremony he gives a heartfelt speech about how much they all mean to him.
The final scene of The Big Bang Theory series finale shows the friends back home in Penny and Leonard's apartment. They're sitting in their usual spots as they eat and look happy together. The theme song plays slowly as the scene fades to black.