Sheldon Cooper is not an easy man to argue with, given his usual quirks and know-it-all attitude, but Penny may have uncovered the secret of dealing with the physicist in the upcoming episode Big Bang Theory season 11.

Episode 5 is titled, The Collaboration Contamination, which will air on Monday (23 October) at 8pm EST on CBS Network. The official synopsis reads as follows:

Sheldon and Koothrappali confide in Bernadette when they can't handle Amy and Wolowitz working together. Also, Penny and Leonard learn new tactics for how to deal Sheldon from an unlikely source.

A promo for the episode opens with the voiceover saying, "What did Penny do to turn this guy [ a clip of Sheldon singing annoyingly in car] into this guy." Then we see Sheldon telling Amy, "You need to sit down and let me pamper you!"

"The secret lies in this little book," says the voiceover, as Leonard asks Penny, "What did you do? Are you a witch?" to which she says, "Its like answer key to Sheldon's test."

Sheldon and Amy, who got engaged in The Big Bang Theory season 11 premiere episode, have been planning their wedding. According to showrunner Steve Holland, this season is certainly building towards a wedding.

He told Deadline, "We are certainly building toward a wedding. The wedding planning is going to play a big part in the season so I wouldn't be surprised if we saw a wedding before the season was over although I can't promise that."

However, there will be a few bumps on road, Holland warned. "I'm sure like anything with Sheldon, there will be bumps along the road. In early episodes that are coming up we deal with that. Sheldon, in his excitement to make the wedding as perfect as he can, takes it over and tries to overthink every decision."

"So I think planning a wedding with Sheldon is going to be a complicated matter even when he is just trying to make it great," the executive producer revealed.