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.

When Ron hexes the day to prove superstitions aren't real, things at the hospital start getting weird; Joyce and Matt discover an employee's secret.

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.

Ron and Bruce butt heads over a candy bar; Alex is forced to fire an incompetent employee; Matt seeks appreciation for saving a patient's life.

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