'The Big Bang Theory' season 11 episode 4 ‘The Explosion Implosion’ spoilers

“The Big Bang Theory” (TBBT) cast, which includes Kaley Cuoco (Penny), Johnny Galecki (Dr Leonard Hofstadter), Jim Parsons (Dr Sheldon Cooper), Mayim Bialik (Dr Amy Farrah Fowler), Kunal Nayyar (Dr Rajesh "Raj" Koothrappali), Melissa Rauch (Bernadette Rostenkowski-Wolowitz) and Simon Helberg (Howard Wolowitz), will have a new episode titled "The Explosion Implosion," which airs in the US on Oct. 16. It will feature Leonard's mum, Beverly (Christine Baranski) bonding with Penny. Plus, Howard and Sheldon will have a road trip to the desert.

Spoiler alert: This article contains 'The Big Bang Theory' spoilers. Read on if you want to know more about 'The Explosion Implosion.'

According to a CBS press release, "The Big Bang Theory" season 11, episode 4 will show Sheldon and Wolowitz driving to the desert. They will shoot off a model rocket, and along the way, the two men will bond over their relationships with their disappointing fathers. Meanwhile, Penny will also bond with Beverly, aka Leonard's mother, which will annoy Leonard. Aside from Baranski, the other stars that will appear in this episode are Michael Patrick McGill (Police Officer) and Dana L Wilson (Dr Samuels).

"The Explosion Implosion" was directed by Mark Cendrowski. The episode's story was written by Tara Hernandez, Bill Prady and Maria Ferrari. Its teleplay was written by Jeremy Howe, Steve Holland and Eric Kaplan. A preview of "The Explosion Implosion" was posted on YouTube by tvpromosdb, and it shows Leonard's mum talking to Penny on the phone. Penny will also tell Leonard about how much she has been chatting with his mother lately. "Let's be clear, I married you to hurt her," Leonard tells Penny in the episode's promo video.

'TBBT' episodes: 'The Relaxation Integration'

The episode of TBBT before "The Explosion Implosion" was "The Relaxation Integration," which aired in the US on Monday. It was also directed by Mark Cendrowski, and it featured Sheldon trying to embrace a more relaxed personality, as suggested by Amy. It was brought about by his anxiety over their wedding planning, particularly the wedding date. Amy even recorded Sheldon while he was sleeping to show him what he has been saying while he was in dreamland. Because of this, Sheldon tried to be more easygoing and even wore flip-flops. Unfortunately, it ended in disaster when he slipped and lost the flip-flop and encountered gross things.

Finally, Sheldon decided to let Amy do all the wedding planning as long as he is allowed to wear a "Star Trek" uniform under his tuxedo. As for Raj and Stuart, they fought over Ruchi (Swati Kapila). However, she's not interested in a relationship with anyone.

Watch "Big Bang Theory" episodes in Australia on Nine Network and on CBS in the US. The sitcom's schedule on CBS is Mondays at 8-8:30 pm ET/PT. Stay tuned for more updates about Sheldon, Leonard, Penny, Raj, Amy, Bernadette and Howard.