The Big Bang Theory' Season 9 Finale: Gear Up for Some New Cast Members and a Shocking Plot Twist

"The Big Bang Theory" is a popular sitcom on CBS network that is based on the lives of four nerds. The show is approaching its ninth season finale, that will leave the fans in a major cliffhanger. The final episode will be aired on May 12 at 8 p.m. EST.

As per previous reports, the last episode of "The Big Bang Theory" will put a face on Leonard's father. Actor Judd Hirsch has been roped in for he role and the episode will be titled "The Convergence-Convergence."

In the finale episode, the plot will revolve around Leonard and Penny who decide to marry again, but this time with all their friends and family members invited. Previously, the couple got married in Las Vegas but now want to renew their vows in front of all the people they love.

To attend their son's wedding, Leonard's parents will be there too. This means that for the first time in the history of the show, Leonard's father will be revealed to the audience.

Leonard's parents got divorced and in this episode, his father will be shown involved with another cast member of "The Big Bang Theory. Rumor has it that Leonard's father will hook up Sheldon's mother, Mary Cooper on the show's final episode.

Meanwhile, Howard (Simon Helberg) receives an email from the U.S. Air Force informing him about a new project. In the final episode, fans can expect to see a lot more action and interesting scenes before the season comes to a close.