Leonard Nimoy tweeted this set photo from The Big Bang Theory, showing the first-ever meeting of Mr. Spock and Star Trek uberfan Dr. Sheldon Cooper (Jim Parsons).

After five years of trying to land Nimoy as a guest star, Big Bang Theory co-creator Chuck Lorre says, "He finally gave up. We caught him."

Nimoy will haunt Sheldon's dreams in an episode entitled "The Transporter Malfunction," which airs on Thursday, March 29th.

[tvline]