Sheldon (Jim Parsons) and Leonard (Johnny Galecki) will turn to desperate measures to buy liquid helium while Amy (Mayim Bialik) will become more open to dating other men in Monday's all-new episode of The Big Bang Theory."

In last week's episode, "The Perspiration Implementation," Amy turned down an offer to go on a date with Sheldon's coworker Barry Kripke, played by John Ross Bowie. However, the synopsis for the next episode, entitled "The Helium Insufficiency," suggests that Amy may begin to consider dating other men now that she knows that Sheldon has started to ask out other women. The two broke up at the end of Season 8. Meanwhile, Penny (Kaley Cuoco) and Bernadette (Melissa Rauch) will try their best to get Amy to embrace the idea of going on dates.

The trailer video also hints that Sheldon and Leonard will buy liquid helium off the black market. In the promo, actor Michael Rapaport appears to be a helium "dealer" who demands the friends pay up if they want helium.

According to CarterMatt, the synopsis reads as follows:

"In the midst of a nation-wide helium shortage, Sheldon and Leonard take desperate measures to get the supplies they need. Also, Penny and Bernadette download a dating app on Amy's phone to try and find her a new man, on THE BIG BANG THEORY, Monday, Oct. 26 (8:00-8:30 PM, ET/PT), on the CBS Television Network. Michael Rapaport guest stars Kenny, a black market dealer."

Later on in the season, British comedian and actor Stephen Merchant and "America's Next Top Model" alum Analeigh Tipton will make guest appearances on the show, reports The Hollywood Reporter.

According to Metro.co.uk, Merchant will play Amy's new love interest, while Tipton will play Sheldon's new love interest.

Season 9, Episode 6, "The Helium Insufficiency," will premiere on Monday, Oct. 26 on CBS.

Watch a preview video below.