The Big Bang Theory season 10 premiere synopsis teases 'awkward morning' for Sheldon and Leonard

Penny's mother and drug-dealing brother will debut in The Big Bang Theory season 10 premiere.

CBS has released the official plot synopsis for the season 10 premiere, which teases the aftermath of Mary Cooper and Alfred Hofstadter sharing an evening together. Episode 1 of TBBT season 10 will air on Monday (19 September) at 8pm EST on the network.

Warning: Potential spoilers ahead

Roommates Sheldon and Leonard will be seen dealing with an awkward morning following the late night shenanigans of their parents. Season 9 of the hit comedy ended on a cliffhanger with fans wondering if Mary and Alfred have hooked up or not.

Besides, Penny's family will be introduced in episode 1. Anxiety-ridden Susan (played by Katey Sagal) and drug-dealing Randall (played by Jack McBrayer) will come to visit the married couple in the chapter.

Here is the full synopsis for Big Bang Theory season 10's premiere episode:

In The Big Bang Theory's season premiere, after Sheldon's mother and Leonard's father share an evening together, everyone deals with an awkward morning the following day. Also, Penny's family arrives for the ceremony, including her anxiety-ridden mother, Susan (guest star Katey Sagal), and her drug dealing brother, Randall (guest star Jack McBrayer).

Breaking Bad actor Dean Norris is set to guest star in a multiple-episode arc in season 10. Norris will play Captain Williams, a tough Air Force representative from the Department of Material Command, who will be interested in Howard and Leonard's quantum gyroscope for military applications.

This implies that Howard's fear of being spied on by the government is not completely baseless.

Dean Norris to guest star on #BigBangTheory, will shake things up for the guys: https://t.co/M28Z80jBsb pic.twitter.com/toXXGtNZPT
— The Big Bang Theory (@bigbangtheory) August 10, 2016

With all the speculations and rumours about the show's season 11 renewal chances, CBS Entertainment president Glenn Geller revealed he is confident the hit comedy will go on beyond season 10.

Geller said at the CBS's Television Critics Association panel, "We are very confident that everyone involved wants more Big Bang beyond Year 10, and we know that Warner Bros. will make these deals."