Leonard Nimoy Leonard Nimoy

We are sad to report that the identity of the actor who is playing the mysterious Dr. William Bell on Fringe has leaked before he could make a surprise appearance on the season finale.

But we are very happy to report that we've confirmed the actor is Star Trek legend Leonard Nimoy! Nimoy's casting, as first reported by the FringeTelevision blog, which we hear is all but a done deal at this point, may finally put to rest all those fan-created conspiracy theories about Dr. Bell (He's a cyborg! He's Nina's prosthetic hand! He's Walter!).

Nimoy is no stranger to J.J. Abrams productions: He also reportedly reprises the role of Spock in a cameo for the wunderkind director's Trek reboot, which hits theaters on May 8. Scuttlebutt says he's a time-traveling, "from the future" Spock, who returns to help the young Spock (Heroes' Zachary Quinto).

Nimoy will first appear in the season finale, then recur throughout next season.

What do you think of Nimoy's casting? A fanboy's dream? Too nerdy?