Nathan Fillion will make a cameo appearance, as himself, on an upcoming episode of The Big Bang Theory.
In the episode, Raj (Kunal Nayyar) and Leonard (Johnny Galecki) see Fillion eating at a restaurant and try to decide if it really is the actor or a look-a-like and whether or not to approach the star to ask for a picture.
Fillion starred in Joss Whedon's Firefly, which is often mentioned in the show, as well as Buffy The Vampire Slayer, multiple DC Comics animated movies and currently stars in Castle.
Fellow Firefly star, Summer Glau, made an appearance in the show also playing herself way back in Season 2.
Nathan Fillion will make his appearance in the February 19th episode.
The Big Bang Theory airs Thursdays on CBS.
(Source: Entertainment Weekly)