Howard Wolowitz finally returns from his time as an astronaut on the International Space Station. Though he's expecting huge fanfare, he instead discovers that Bernadette has asked the guys not to show up at the airport, so that she can have Howard all to herself. Unfortunately, she's got a serious cold which ruins his romantic homecoming evening.
Meanwhile, Sheldon, Leonard, Penny, and Amy are having a game night, with teams of boys versus girls. After the girls quickly beat the boys at Pictionary, they challenge them to a series of other games that test both mental and physical agility.
Howard looks for something else to do for the evening. He goes to his mother's house, only to discover that she's having a relationship with Howard's dentist. Then he goes to Raj's house, only to discover that Stuart has filled his role as "best bud" and is now living with Raj.
This Episode's Science
The main science from this episode has to do with Howard's return from outer space. There is one brief mention of the Higgs boson while Sheldon is proposing that the gang play a made-up game called Physics Fiesta.