‘Big Bang Theory’
How will Sheldon (Jim Parsons) help Leonard (Johnny Galecki) and Penny (Kaley Cuoco) with their marital issues in "Big Bang Theory" Season 10, episode 13? CBS

“Big Bang Theory” Season 10, episode 13 is expected to be another hilarious episode centered on Sheldon (Jim Parsons), Leonard (Johnny Galecki), Amy (Mayim Bialik), Penny (Kaley Cuoco) and their friends.

In the promo released by CBS for “The Romance Recalibration,” Leonard and Penny’s marriage will be in trouble because of their differences. In an attempt to save their relationship, Leonard asks Sheldon to help him write a relationship agreement with Penny. Sheldon is more than willing to help because he previously made a similar agreement for him and Amy (Mayim Bialik). In fact, when Sheldon breaks into laughs, Amy immediately follows his lead. A confused Penny wonders why Amy is laughing, and she tells her that it’s also part of her and Sheldon’s relationship agreement.

In the same episode, Penny and Amy will have plenty of time to bond with each other. When Penny gets upset with Leonard, she decides to not invite him on their usual spa date. Instead, Penny asks Amy to join her. Leonard will be alarmed by Penny’s decision and will do his best to fix their marriage before their issues get bigger.

Meanwhile, “Big Bang Theory” Season 10, episode 13 is supposed to air on Thursday, Jan. 12, but the episode was moved to Jan. 19. It is unclear why CBS decided to put the new installment on hold since the sitcom just returned from a short winter hiatus last week, Jan. 5.

In other news, the fate of “Big Bang Theory” Season 11 remains to be unknown. CBS entertainment president Glenn Geller told Variety at the Television Critics Association winter press tour that Cuoco, Parsons and Galecki are in talks to return for at least another season of “Big Bang Theory.”