David Theune

When Howard dresses up as Sheldon for Halloween, Sheldon seeks retaliation at Leonard and Penny’s Halloween party; Meanwhile, Leonard is shocked that Penny doesn't remember their first kiss.

While Raj is worried that people won’t take him seriously in his own field after publishing a paper suggesting he may have discovered alien life, Penny encourages Leonard to stand up for himself when he wants to be the principal investigator on a plasma physics study.

Alex accidentally provokes the Emergency Department's mean girls; Ron and Serena battle over parking etiquette; Bruce has a hard time letting go of the spotlight.

Joyce launches a women's health initiative to unexpected results; Ron treats a patient who has all the answers; Bruce has an existential crisis.

Bruce and Alex give conflicting medical advice to a young athlete; Joyce competes with Tiger Woods in her alumni magazine; Matt and Serena (almost) drop an unconscious patient.

At the annual fundraiser, Alex and her husband, Tim, try to have a wild, kid-free night; Ron and Joyce butt heads over hosting duties; Bruce sets out to win this year's "Dancing with the Caregivers" competition.