A young grad student's attraction to Sheldon confuses everyone including Sheldon himself.

In the eleventh season premiere, Amy gives Sheldon an answer to his proposal, while Howard and Bernadette struggle with some unexpected news. LAURIE METCALF returns as Sheldon’s mother, Mary; RIKI LINDHOME returns as Ramona; and STEPHEN HAWKING returns as Himself.

On the tenth season finale, the gang is concerned when Sheldon’s former admirer, Dr. Ramona Nowitzki (returning guest star RIKI LINDHOME) resurfaces while Amy is away at Princeton.

When word spreads that Lorelai was the one who proposed, Luke is embarrassed; Lorelai, still angry at Rory for dropping out, tells Emily and Richard that they can care for her now.

A vengeful Schmidt targets Jess and Nick’s relatively happy relationship. Meanwhile, when Winston learns that Furguson the cat must be neutered, he is determined to give this feline one last night of carnal glory.

When Luke agrees to build sets for the elementary school's production of "Fiddler on the Roof," he knows that Lorelai is the costume designer and hopes that their paths will cross.

On the eve of Lane and Zach's wedding, party plans for both sides of the wedding party go awry.

Agents Prentiss and Todd go undercover to profile a serial killer whose skillful persuasion lures women into danger.

When Rory's former boyfriend Jess (Milo Ventimiglia) shows up at her grandparents' house, she is pleased to hear about new developments in his life and agrees to have dinner.

Brennan and Booth investigate the body of a man murdered for the undisclosed contents of a briefcase; early evidence leads the team to suspect secret operatives are at work, and their theories are supported when the liquefied remains of a CIA agent are discovered in the trunk of a car; meanwhile, Brennan's best-selling book leads to financial success, and serves as a point of contention with Booth; and Jeffersonian intern Wendell loses his scholarship.

Louis must bring his family on a business trip to Gator World; Jessica learns to relax; Evan's last baby tooth falls out.

Amy and Tyler confront emptiness; Dougie gets a promotion at work.

Miss Piggy is angry when Kermit books Elizabeth Banks as a guest on "Up Late With Miss Piggy"; Fozzie Bear gets acquainted with his girlfriend's parents; Imagine Dragons perform.

Amy attempts to generate interest in a woman's group at work.

A fellow group therapy alumna from Hawaii comes to visit Amy.

The feud between Miss Piggy and Reese Witherspoon hits a new level when the two volunteer for Habitat for Humanity; Fozzie's relationship hits a snag.

Chelsea Handler makes things interesting for Scooter when he books her; a double date reveals that Becky may have a suspicious past.

Amy and Tyler meet with Jeff at a jazz club; Abaddonn's breach of security is exposed; Krista has a complication with her pregnancy.

Amy gives Tyler a warning; Amy tells her mother about the exposé; Amy is taken to meet with Szidon and Abaddonn lawyers.

Even though they know they are under a spell, Buffy, Dawn, Anya and even Willow can’t stop themselves from falling in love, and fighting over, a high school quarterback.