'The Big Bang Theory' Season 9 Spoilers: Patent for Boys' Ideas Coming Up in Episode 18

REUTERS / Mario AnzuoniKaley Cuoco (C) accepts the award for favorite network TV comedy series with the cast and crew of "Big Bang Theory" at the People's Choice Awards 2016 in Los Angeles.

"The Big Bang Theory" season 9's next episode will be interesting because the boys will try to patent their ideas and there will be pregnancy-related discussion among the girls.

In the previous episode of "The Big Bang Theory" season 9, Sheldon Cooper's (Jim Parsons) friends surprised him with a special birthday celebration, even though he does not really like both surprises and parties. Because it was also the show's 200th episode, returning stars from previous seasons graced the occasion, Design & Trend recalls.

The guest stars in "The Big Bang Theory" season 9 episode 17 titled "The Celebration Experimentation" included Adam West, Will Wheaton, and Sara Gilbert, the report adds.

Series co-creator Bill Prady had earlier revealed to The Toronto Sun that the episode 17 will be huge and fun because of the guest stars. Mayim Bialik, who plays Sheldon's girlfriend Amy on the show, said the episode was fun because of the way the characters pulled off the birthday surprise, the report relays.

Episode 19, which is titled "The Application Deterioriation," will see the guys trying to get their ideas patented. Based on the official synopsis for the upcoming episode, Sheldon will draft a contract stipulating how the boys will divide their shares, Hollywood Hills reports.

The next episode will also feature the girls' conversation about Bernadette's morning sickness. They will then spend some time together before going to the boys' apartment.

Emily and Claire, on the other hand, will communicate with Raj, the report adds.

Meanwhile, "The Big Bang Theory" has already been renewed for its 10th season. However, series co-creator Chuck Lorre revealed that the plot for season 10 is still not in place because they are still preoccupied with the current installment. As of now, the writers are still busy crafting the stories for episode 9.

"The Big Bang Theory" season 9 episode 18 airs on Thursday, Mar. 10 at 7 p.m. CT on CBS.