Mensa-fied best friends and roommates Leonard and Sheldon, physicists who work at the California Institute of Technology, may be able to tell everybody more than they want to know about quantum physics, but getting through most basic social situations, especially ones involving women, totally baffles them. How lucky, then, that babe-alicious waitress/aspiring actress Penny moves in next door. Frequently seen hanging out with Leonard and Sheldon are friends and fellow Caltech scientists Wolowitz and Koothrappali. Will worlds collide? Does Einstein theorize in the woods?
The gang deals with the awkward aftermath of an overnight liaison between Sheldon's mum and Leonard's dad. Penny's dysfunctional family is in town. S10, Ep1
An Air Force bigwig approaches the guys about their revolutionary invention, and Bernadette is upset with Penny after she accidentally leaks a secret. S10, Ep2
Howard and Leonard are putting in late nights at work, Raj and a pregnant Bernadette spend a day together, and Penny and Amy take in a faculty party. S10, Ep3
Cohabitation Experimentation. Sheldon and Amy decide to move in together. Meanwhile, Howard and Bernadette become upset when Raj learns the gender of their baby before they do. S10, Ep4
Sheldon accuses Amy of not following the bathroom schedule. Meanwhile, Howard and Bernadette's staycation is interrupted by hot tub interlopers. S10, Ep5
Feeling his baby kick sends Howard on a baby-items buying binge with Raj, Sheldon and Amy host a brunch, and Penny is invited to a sci-fi convention. S10, Ep6
Amy fibs about repairs being made to her apartment. Later, they present an episode of 'Fun with Flags' in Penny's apartment. S10, Ep7
A successful gene experiment leaves Sheldon excited to procreate with Amy. Raj is reluctant to reveal what his new woman does for a living. S10, Ep8
A coworker's MacArthur Genius fellowship award leaves Sheldon stone cold jealous. Howard finds a remote-control Stephen Hawking action figure. S10, Ep9
Property Division Collision. A divide develops between Sheldon and Leonard when divvying up their shared belongings. Raj and Stuart battle to provide Bernadette the most help. S10, Ep10
While Sheldon and Amy celebrate Amy's birthday, Howard and Bernadette welcome their new Baby Wolowitz. S10, Ep11
Sheldon and Amy visit Leonard and Penny for the first time since the holidays and share details about their terrible trip to Texas. S10, Ep12
After a disagreement, Penny takes off for a spa weekend, and Sheldon plays peacemaker. Howard and Raj battle a noisy floor in the baby's room. S10, Ep13
Emotion Detection Automation. Sheldon tests an MIT invention, Leonard has trouble when Penny announces her brother's visit, and Raj seeks advice from old girlfriends. S10, Ep14
Leonard and Howard engineer a distraction for Sheldon to keep him from hindering progress on the guidance-system project. S10, Ep15
Amy is incensed when she learns Sheldon has shared intimate relationship information, and Raj's father stops sending financial support. S10, Ep16
Raj finds himself in a cash crunch and turns to Sheldon to help him. Meanwhile, Penny considers crashing the guys' annual Comic-Con getaway. S10, Ep17
Escape Hatch Identification. Leonard and Penny offer Sheldon's old room to Raj after he moves out of his apartment. S10, Ep18
Raj moves in with Leonard and Penny, and a period of adjustment begins, while usually self-centred Sheldon shows surprising interest in Amy's work. S10, Ep19
Sheldon is pushing himself with too many collaborations. Bernadette's maternity leave is running out, and she must face going back to work. S10, Ep20
Leaving the baby in daycare proves to be tough for Bernadette, and geologist Bert digs up a girlfriend, but some colleagues think she's a gold digger. S10, Ep21
Leonard isn't thrilled when Penny considers taking a new job offered by her ex-boyfriend, Zack. S10, Ep22
Leonard, Sheldon and Wolowitz celebrate the completion of their top-secret military project, until an unpleasant surprise leaves their heads spinning. S10, Ep23
Sheldon's former admirer, Dr. Ramona Nowitzki, turns up while Amy is visiting Princeton, and the gang is extremely concerned. S10, Ep24