The Big Bang Theory Season 9 Episode 4: The 2003 Approximation

A new episode of The Big Bang Theory, titled "The 2003 Approximation," airs tonight on CBS.

In "The 2003 Approximation," Sheldon learns of an impending change in his living arrangements and decides to revert back to 2003, a simpler time before he met Leonard and Penny. Also, Howard and Raj form a band to play at the Comic Book Store.

Check out the videos below to see a preview of the episode and two sneak peeks.

"The 2003 Appeximation" is written by Chuck Lorre, Steve Holland and Eric Kaplan, and directed by Mark Cendrowski.

The Big Bang Theory, "The 2003 Approximation," airs Monday, October 12, 2015 at 8 p.m. ET on CBS.