'The Big Bang Theory' season 10 episode 12 spoilers: The gang recaps their horrible holidays; how will Bernadette and Howard deal with their new baby?

The gang recaps their horrible holidays on the upcoming winter premiere of CBS' top-rating sitcom "The Big Bang Theory" season 10.

Thursday's fall finale of the CBS comedy saw Bernadette (Melissa Rauch) as she finally gave birth to Halley. The episode also featured Amy (Mayim Bialik) and Sheldon's (Jim Parsons) annual coitus adventure, which somewhat didn't go as planned. Frustratingly, Amy keeps getting interrupted by her friends — first by Penny (Kaley Cuoco) and Leonard (Johnny Galecki) telling them that Bernadette is delivering the baby, then by Sheldon who gets mad at her when he found out that she visited the Wizarding World of Harry Potter without him, and lastly, by Raj (Kunal Nayyar) who's been kicked out by everyone else because he was being annoying.

When the series picks up next year, viewers will see how Bernadette and Howard (Simon Helberg) will deal with their new bundle of joy. "You'll get a taste of it in the first episode back in January," executive producer Steve Molaro told Entertainment Weekly. "The entire gang and Stuart, all eight of them, are back having dinner in the living room like old times, recapping how their horrible holidays went," he went on to say.

As for the rest of the characters, Molaro confirmed that Laurie Metcalf will return in the episode to reprise her role as Sheldon's religious and conservative mom, Mary. It turns out that Sheldon and Amy spent their holidays in Texas to let Mary know that "they're living in sin together." While Howard and Bernadette deal with the baby and Sheldon and Amy are in the Lone Star State, Penny and Leonard are having the time of their lives.

Describing the newlyweds' holidays as "ridiculously fun," Molaro hinted that Penny and Leonard's seemingly exciting vacation eventually takes a turn for the worst "Leonard and Penny are out having the best Christmas ever, until they decide to go to a farm and chop down their own tree," he continued. "It just spirals down real fast."

"The Big Bang Theory" season 10 returns to the small screen on Thursday, Jan. 5 at 8 p.m. ET on CBS.