Sheldon makes a scientific discovery, but it ends up making him feel like a cheater. When Howard romances Bernadette, Penny decides to try it with Leonard.
Dottie makes an unexpected connection when she meets a fellow stroke survivor at physical therapy. Bob and Douglas try to keep tabs on Christina while she's away at an emotional wellness spa.
Sheldon is bullied by an unlikely character, and Mary and George disagree on how to handle the situation.
Penny tries to throw a wrench into Leonard's plan to be a sperm donor for her ex-boyfriend. The gang turns Raj's canceled bachelor party into a couple's trip aboard the "vomit comet."
The gang will do anything to join Wil Wheaton's celebrity Dungeons and Dragons game with William Shatner, Joe Manganiello, Kareem Abdul-Jabbar and Kevin Smith.
Sheldon is miffed that Leonard plans to attend a party hosted by his nemesis, Wil Wheaton.
A kit for teaching how to create cuddly animal characters; a trussing device designed to cook the perfect bird; a company that provides convenient personal storage for medical necessities,
Bash treats a man with a rare medical condition. Mags gets a visit from her parents, and goes above and beyond for a pregnant woman with an undiagnosed condition. A misunderstanding with a rabies patient lands Theo in trouble.
Jamie and Joe search for an undocumented teenage girl who has been sex-trafficked. A woman in witness protection is murdered. Frank calls out the district attorney's office for instituting a new rule that classifies armed robbery as a misdemeanor.