With reporting by Josh Horowitz

What's in a name? Well, we still don't know Domhnall Gleeson's character's name in the highly anticipated "Star Wars: The Force Awakens," and Oscar Isaac, his co-star in both that film and the upcoming "Ex Machina," doesn't know how to spell Gleeson's real name either.

At South by Southwest Film Festival in support of "Ex Machina," MTV News caught up with the duo and gave Isaac a little pop quiz.

"Yeah," Isaac said when asked if he could spell the Irish Gleeson's first name, then immediately tripped up.

"Oh, he's done it," Gleeson said.

Jokes and tricky names aside, Isaac and Gleeson are still holding mum on "Star Wars" details. When speaking with MTV News, Gleeson said, "I feel like I just had a stroke." Gleeson wouldn't even confirm that he's in "Star Wars." Or that Isaac, whose character we've seen in the trailer already, is in it either, for that matter.

"Oscar's in the trailer, sure, but he might not be in the movie," Gleeson said.

Well played, sir.

Check out more from Isaac and Gleeson in the interview below.

"Ex Machina" hits theaters April 10, 2015.