Ian McKellen: 'Silly' Stephen Colbert Cracked Under 'Hobbit' Excitement

If anyone can crack Stephen Colbert, it's Gandalf.

our editor recommends

'Hobbit' Director Peter Jackson Gets Grilled by Stephen Colbert (Video)

'Hobbit' Star Martin Freeman: 'I'm Geek Royalty Now'

The Comedy Central host and devout J.R.R. Tolkien devotee staged "Hobbit Week" on his show, inviting several series stars and the director, Peter Jackson, as his guests. Kicking off the week Monday was Ian McKellen, who joined Colbert on a set decorated to resemble Bilbo Baggins' house in Bag End. Colbert was extremely enthusiastic the entire evening, and McKellen noticed something a little unusual about him during their conversation.

VIDEO: Ian McKellen and Stephen Colbert Geek Out

"We had a very good, fun time. I still don’t know whom I was talking to -- whether it was the real Stephen Colbert," he said, laughing. "I think it perhaps was more than usual. He’s such an expert on Tolkien, he really is, he can quote it at length, and he was genuinely enthusiastic about meeting the cast, which he’s doing right through this week. So the silly Stephen Colbert, who is normally on the program, rather dropped away. It was interesting to watch."

It took McKellen telling Colbert that he is gay to activate the faux-conservative pundit that the Peabody winner normally portrays, but even then, the effect was only temporary.

McKellen also told THR that he almost had some trouble dealing with his on-set counterparts while filming The Hobbit; given the computer trickery required to create the size difference between himself (as Gandalf) and the 12 dwarves with whom he traveled.

"They provided me with pictures of the dwarves, relative to where they would be on their own set, and whoever was speaking lit up, and I could hear their voice through an earpiece," he explained. "But I was on my own with my own camera that was shooting me at the same moment that they were being shot. I don’t understand it, but all I know is that I was pretending to act with 13 people who weren’t actually there."

Email: Jordan.Zakarin@THR.com; Twitter; @JordanZakarin