The Big Bang Theory season 8, episode 4 airs tonight on CBS! Here’s a new clip, and everything else you need to know about “The Hook-Up Reverberation.”

Penny will find herself drawing the ire of Raj’s girlfriend Emily when The Big Bang Theory season 8, episode 4 airs tonight at 8:00 p.m. The episode, titled “The Hook-Up Reverberation,” will focus on Penny’s confusion when Emily seems to dislike her.

“Raj’s honesty about his past comes back to haunt him after his girlfriend, Emily, is cold to Penny,” the synopsis from CBS teases. “Also, the guys consider becoming part-owners in Stuart’s comic book store.”

Last week on The Big Bang Theory, Howard desperately tried to figure out how to throw a decent first pitch before striking out (so to speak) in front of a stadium full of Angels fans. His decision to use The Science worked…until it didn’t.

Meanwhile, Sheldon and Amy gloated over their superior relationship, which exposed Penny and Leonard’s uncertainty about their engagement. Thankfully, their feelings for each other were strong enough to settle their fears – for now, anyway.

The preview for “The Hook-Up Reverberation” focuses on the guys and their we-can-already-tell-this-is-ill-advised plan to buy the comic book store.

Yes, this is going to go well.

A new clip from The Big Bang Theory season 8, episode 4 introduces Penny having a few concerns about Emily.

Still photos from the episode also focus on the ladies, featuring the lovely Laura Spencer as Emily.

Where to watch ‘The Big Bang Theory’ online:

Catch The Big Bang Theory season 8, episode 4 on CBS.com. New (and old) episodes are also available for purchase on Amazon and iTunes.

The Big Bang Theory season 8, episode 4, “The Hook-Up Reverberation,” airs tonight at 8:00 p.m. on CBS.

What are your hypotheses for ‘The Hook-Up Reverberation’?