The Big Bang Theory

What did she say? Amy (MAYIM BIALIK) answers Sheldon’s marriage proposal. Meanwhile, Howard & Bernadette struggle with some unexpected news.

Leonard’s job is at stake when he gives an embarrassing radio interview which angers the university and the entire physics community. NPR Host IRA FLATOW returns as himself.

Amy records Sheldon talking in his sleep and tries to convince him he can be more easygoing. Meanwhile Raj and Stuart compete to win the heart of Bernadette’s coworker.

While Howard and Sheldon bond over their relationships with their disappointing fathers, Leonard’s mom (CHRISTINE BARANSKI) finds a new best friend in Penny.

Leonard and Penny learn new tactics for dealing with Sheldon from an unlikely source. Meanwhile, Raj & Sheldon can’t handle Amy working together with Howard.

Sheldon goes up against WIL WHEATON for the role of the new Professor Proton, while Penny steps in to take care of Halley when Bernadette & Howard are laid up on bed rest.

Sheldon and Bert collaborate on a research project, despite Sheldon's embarrassment. Penny and Bernadette coach Koothrappali on how to navigate his relationship with Ruchi.

Sheldon and Bert collaborate on a research project, despite Sheldon’s embarrassment. Meanwhile, Penny and Bernadette coach Raj on how to navigate his relationship with Ruchi.

Leonard and Howard enlist Barry Kripke (JOHN ROSS BOWIE) to help after they learn Sheldon betrayed them by working with the military behind their backs.

Leonard and Howard are furious after they learn Sheldon went to work with the military behind their backs. Bernadette is on bed rest, and she asks Raj to do some digging when she suspects Ruchi is trying to steal her job.

The gang flashes back to 2010 as Leonard tries to remember where he kept a potentially valuable investment.

Sheldon tries to teach the guys a lesson after they cut him out of a potentially valuable Bitcoin investment. Also, a seven-year-old video reveals a secret about Leonard and Penny's relationship.

Sheldon & Amy develop a unique system to eliminate stress from wedding planning. And Raj “breaks up” with Howard after realizing he’s hurting his confidence.

Sheldon plans an authentic Little House on the Prairie dinner for Amy’s birthday, while Leonard laments his own lack of accomplishments at Christmastime.

Sheldon and Amy subject their friends to a series of secret experiments to discover who would be the most qualified to be Best Man and Maid of Honor at their wedding.

While Penny helps Sheldon figure out his next move in science, Bert, the geologist, replaces Howard in his band, “Footprints on the Moon.”

Raj is caught between a rock and a hard place when he discovers he’s dating a married woman (BETH BEHRS). Sheldon rents his old room back for a place to work.

While Sheldon petitions Wil Wheaton to appear on the new Professor Proton show, Leonard finds himself in an awkward spot after he asks his friends for feedback on his novel.

When Bernadette won’t go into labor, all her friends try to help out; and Howard learns that Bernadette has already chosen their son’s name.

While Leonard struggles to secure the perfect wedding venue for Sheldon and Amy, Howard and Bernadette struggle with who should work and who should stay with the kids.

When Penny gets the opportunity to host BILL GATES at work, Leonard, Howard and Raj try to meet him, while Sheldon thinks it’s a prank.

Leonard runs against Sheldon for President of the Tenants Association. Meanwhile, Bernadette sends Howard and Raj out to find the owner of a drone that crashed in their yard.

While Penny and Bernadette improvise a bachelorette party for Amy, Sheldon and the guys visit a reclusive scientist in his cabin in the middle of nowhere.

Writer NEIL GAIMAN puts Stuart’s comic book store on the map. Meanwhile, friendships are threatened when Raj takes credit for Penny’s astronomical discovery.