'The Big Bang Theory' season 10 air date news: Penny's marital bliss marred by family troubles? Sheldon and Leonard as stepbrothers?

"The Big Bang Theory" season 10 is returning to the small screens in a little over two weeks, and fans are in for another juicy sneak peek of the tenth installment's premiere episode.

There will be new faces gracing the series in guest and recurring roles, one of which is "Under the Dome" actor Dean Norris. According to CBS, Norris will appear in multiple episodes as Captain Williams, a tough Air Force representative who will show interest in Howard (Simon Helberg)and Leonard's (Johnny Galecki) quantum gyroscope. Since Captain Williams is from the Department of Material Command, he will see how the contraption may be used for military operations.

However, tough guy from the Air Force aside, it looks like Leonard has bigger things to worry about, what with his dad Alfred (Judd Hirsch) and Sheldon's (Jim Parsons) mom Mary (Laurie Metcalf) possibly hooking up on the night of his pre-wedding dinner. It appears the two oldies went for a nightcap, but who's to say they didn't cross the line? Cinema Blend notes that the probability of Sheldon and Leonard becoming stepbrothers is high. Talk about awkward. Still, the showrunners are yet to confirm this angle.

Spoilers for "The Big Bang Theory" season 9 also suggest that Penny (Kaley Cuoco) will be going through an awkward family drama, too. Her mom Susan (Katey Sagal, "Sons of Anarchy") will be dropping in for Penny's wedding along with her troubled Randall (Jack McBrayer, "30 Rock").

Speaking at the San Diego Comic Con 2016 in July, the show's producers described Susan as "stressed out and neurotic from a life dealing with her troubled—yet cheerful—son, Randall." Apparently, Randall is an ex-con and a drug dealer.

It definitely looks like the tenth installment of CBS' hit comedy series will be one for the books. It remains to be seen how these new cast additions will fare with series regulars Raj (Kunal Nayyar), Emily (Laura Spencer), Bernadette (Melissa Rauch), and Amy (Mayim Bialik).

"The Big Bang Theor" season 10 will air on Sept. 19 at 8 p.m. EST on CBS. Keep coming back for more news and updates on series.