Thursday night on "The Colbert Report," host Stephen Colbert welcomed Carey Mulligan, one of the stars of Baz Luhrman's reboot of "The Great Gatsby." Colbert said that, given the two weeks he had to prepare for the show, of course he read the book first.

"Which I really enjoyed," he said. "And I definitely did do."

However, when faced with Mulligan, who starred in "An Education" and "Drive," it became clearer and clearer that Colbert hadn't read the book and was faking it.

"I just, you know," he said to the Oscar-nominated actress, "I just love how he's constantly...Gatsby-ing? But in a really great way? You know?"

"So, for me," he went on, "the question is: Great Gatsby? Or, the Greatest Gatsby? I'm gonna go with Greatest Gatsby."

Looking mystified, Mulligan asked, "Have you read the book?"

"Oh, yes," he replied.

"Stephen," she said skeptically. "How much of it?"

"Some of it," Colbert tried, before finally admitting, "Okay, none of it."

Mulligan then admitted that she's never read the book either. In fact, she said, she can't read at all. In movies, she said, producers do the "talking dog trick," where they put peanut butter on the roof of her mouth, then dub in the dialogue while she licks it off.

The two then embarked on a special adventure to "The Reading Rainbow," where LeVar Burton patiently explained to them the importance of reading and the deeper meanings of F. Scott Fitzgerald's novel.

Watch the video, embedded below via Comedy Central: