'The Big Bang Theory' Finale May include a Shocking Cliffhanger (WATCH)

With the season finale of CBS comedy series "The Big Bang Theory" approaching Thursday night, all the talk is around drama and not necessarily the witty comedic elements the show is known for.

A storyline cliffhanger could leave fans wondering how Penny and Leonard 's relationship will end up, even though it's now the best it's ever been, CBS News reports. Simon Helberg, who plays Howard Wolowitz on the sitcom, spoke to the network news source in an interview, divulging a possible twist in plot-lines.

"This time, the adventure is for Leonard," Helberg said. "Howard finds Stephen Hawking's crew is sending out an expedition to the North Sea, and he gets Leonard a job, going on a boat for four months."

Leonard, played by Johnny Galecki, debates leaving Penny, played by Kaley Cuoco, and ruining a relationship that has had its ups and downs. But Penny isn't the only one holding Leonard back, according to CBS. His socially awkward genius roommate Sheldon Cooper, played by Jim Parsons, is paranoid about being left alone, and not having his "every whim" catered to.

Romantic troubles could be in store for Raj, played by Kunal Nayyar, and his new love interest Lucy, played by Kate Micucci. While love-life disappointment is nothing new for Raj, he again wants more than Lucy may be able to offer.

"The Big Bang Theory" has spent six seasons on CBS, according to the network, with TBS also running reruns of the series nightly. The first-run episode of the season set a record at 20 million viewers.