NEW YORK, Feb 4 — The "Castle" star will share the screen with the Pasadena geeks in an episode set to air February 19 on CBS.

In a few weeks, Nathan Fillion will make a cameo on "The Big Bang Theory," the most watched comedy in the US. The star of the ABC crime drama "Castle" will play himself in an episode in which Leonard (Johnny Galecki) and Raj (Kunal Nayyar) recognize him in a restaurant. EW.com broke the news of this special guest appearance.

Outside of his role as Richard Castle, Fillion is something of a geek icon thanks to his roles on "Buffy the Vampire Slayer," "Firefly" and "Dr. Horrible's Sing-Along Blog," all created by "Avengers" director Joss Whedon. — AFP-Relaxnews