On Thursday, CBS will air an all-new episode of "The Big Bang Theory," in which Sheldon Cooper's life will take a dramatic turn while he faces a personal crisis.

A promo for the upcoming episode, "The Relationship Diremption," shows that Sheldon will come to the conclusion that he's wasting his time with string theory and will begin to consider giving up on physics. To cope with this inner conflict, Penny decides to give him a makeover and a new hairdo. However, Sheldon's girlfriend Amy doesn't like his new look and fears that he has become too hot to handle.

"I suppose I could see myself in a scientific boy band. Of course, I'd be the dreamy one and the smart one," says Sheldon while admiring his new do in the teaser video.

"What did you do?" asks Amy, who clearly disapproves of Sheldon's new look. "I don't need other girls to see him walking around like sex on a stick."

In the meantime, Raj, Emily and the Wolowitzes go on a double date that ends up with Howard being embarrassed. Barry Kripke will also make a return appearance, reports TV Fanastic.

According to Hypable, the official synopsis for episode 20 states: "Sheldon faces a personal crisis after deciding he's wasting his time with string theory. Meanwhile, a double date between Raj, Emily and the Wolowitzes ends in embarrassment for Howard."

"The Big Bang Theory" S7E20, "The Relationship Diremption," will air on Thursday, April 10 at 8:00 p.m. EDT on CBS.

Watch a preview below.