The Big Bang Theory is one giant ode to unhappiness, so it makes sense that over the years the show has featured guest stars from the biggest geek franchises in film and television. Star Trek: The Next Generation star Wil Wheaton even ended up playing an evil version of himself for a number of episodes, and many other actors joined in the fun. no seriously there are a tone of the Star Trek cast. who guest starred on The Big Bang Theory. But in season seven, it was time for the stars of another big sci-fi franchise to shine when superfan Sheldon Cooper (Jim Parsons) tried to create his own Comic-Con.

In "The Conventrum Conundrum", Sheldon manages to find the voice of Darth Vader himself: the late, great James Earl Jones, playing himself, while dining at a local sushi restaurant. Unlike Sheldon's interactions with many other celebrities, Jones is actually excited to spend time with him and they end up having an adventure together. They sing karaoke, go to a carnival, and even end up pranking the woman who played Princess Leia — the late, great Carrie Fisher, who also plays herself — by ringing her doorbell and running away. It's all great fun, but it turns out the people behind the show really wanted to try to get another Star Wars actor. Unfortunately, he wasn't interested.

In the oral history bookThe Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series” by Jessica Radloff (via TVLineCasting director Nikki Valko revealed that while they were able to get the voice of Darth Vader and the actor who played his daughter Leia, they just couldn't convince the man who played the abusive nerd player Han Solo to sign on. In news that shouldn't really surprise anyone, Valko said Ford was a difficult addition:

“We were going to love Harrison Ford, but it never got any traction. He just wasn't open to it.

Ford isn't one to suffer fools easily and doesn't do much he doesn't want to, so it's no shock that he wouldn't be interested in something like The Big Bang Theory. While he embraced his Star Wars connections and intense fandom, he is also a bit sick of certain questions from fans and he seems to chase roles that take him far away from a galaxy far, far away whenever possible. While it's unfortunate that Ford didn't want to appear, the two actors who did decide to appear had a lot of fun.

The "convention puzzle" gave a chance for Fisher and Jones will meet in person for the first timesomething they surprisingly didn't do despite starring together in one of the most famous films of all time. (Jones recorded his lines elsewhere, and Fisher co-starred with Vader actor David Prowse.) One can only imagine their meeting, perhaps with a little "Carrie ... I'm your father" humor, and the two titans sci-fi knocked their cameos out of the park. Fisher, who unfortunately died suddenly just two years after the episode, is perfect as a slightly more aggressive version of herself, fed up with Jones' antics.

The adorable fictional father-daughter duo weren't the only Star Wars actors to appear on the hit series. Mark Hamill, who played Leia's twin brother Luke Skywalker in the Star Wars films, also appeared in the Season 11 episode "Bow Symmetry". Hamill's only regret was not knowing the series too good when he did the cameo, but later he watched the whole thing while walking on the treadmill and fell in love with the humor of the show.

It's unfortunate that Ford didn't think The Big Bang Theory cameo was worth the effort, but it's great that some of the other Star Wars actors gave it a shot and enjoyed it in the process.