The Big Bang Theory Season 8
The Big Bang Theory Season 8 poster CBS

The hit comedy show The Big Bang Theory Season 8 episode 4 airs today, Monday, 6 October at 8:00 pm ET on CBS.

The fourth episode is titled 'The Hook-Up Reverberation,' and in it Penny will finally meet Raj's new girlfriend Emily (Laura Spencer).

The episode synopsis reads:

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

You can log on to the official website for broadcast details and to watch episodes online.

You can also click here to watch the episode online via live stream.

Preview clips and stills from the episode suggest that the geeky gang will try to help Stuart re-start the comic book store, which was destroyed in a fire near the end of last season.

Another sneak peek shows the gang discussing dinosaurs and Raj talking about finally introducing his girlfriend to everyone. According to the synopsis, things will not go well between Penny and Emily.

Here are a few promotional pictures:

The big bang theory season 8 episode 4
Raj with his girlfriend Emily CBS
The Big bang theory season 8 episode 4
Sheldon and gang meet Raj's girlfriend Emily CBS
The big bang theory
Penny and Emily will not get along with each other CBS
The big bang theory season 8
Sheldon and co decide to help Stuart re-start his comic book store, and become partners. CBS