"Prepare yourself for a rigorous touching."

In episode 4 of CBS' "The Big Bang Theory" Season 9, Leonard (Johnny Galecki) finally cut the chord and moved in with Penny (Kaley Cuoco) -- you know, his wife -- leaving Sheldon (Jim Parsons) on his own across the hall in their original apartment. However, just because Leonard lives elsewhere does not mean the pair can not hang out. In fact, the synopsis for episode 5, "The Perspiration Implementation," reveals Sheldon and Leonard will take up a rather unconventional hobby.

According to the synopsis for episode 5, Penny accuses her new husband of not having the coordination to play sports -- In the promo, she tells him to stick with Scrabble. Leonard disagrees. That will lead the whole gang -- Leonard, Sheldon, Howard (Simon Helberg), and Raj (Kunal Nayyar) -- to decide to take a fencing lesson. Their teacher will be none other than Barry Kripke (John Ross Bowie) and that might be a problem. The synopsis reveals that Barry will catch some feelings for Amy (Mayim Bialik) and that will not make Sheldon too happy. Plus, the promo for the episode reveals that the boys will have some fun with Barry's insistence that the term for striking someone with a fencing sword is a "touch" (see Sheldon's line above). 

Meanwhile, when Stuart (Kevin Sussman) struggles to get female customers at the comic book store, Penny, Amy and Bernadette (Melissa Rauch) come by to help him out. What is their plan? 

Watch the promo for episode 5 below:

How will the boys' experimentation with fencing turn out? Fans will have to wait to find out. "The Big Bang Theory" airs Mondays at 8 p.m. EDT on CBS.