'Sherlock Holmes' gets an action-packed facelift this Christmas with a leaner, tougher Robert Downey Jr. kicking butt in the title role and 'Lock, Stock and Two Smoking Barrels' director Guy Ritchie at the helm. Now, ET's Kevin Frazier is with the pair to deduce some new 'Sherlock' secrets -- if only he could get a word in edgewise with the wisecracking RDJ!

No one's a tougher critic than Robert himself, and he says that the first hurdle was getting used to the idea of an American playing the iconic British character, created by writer Arthur Conan Doyle: "Initially when I heard I was cast in the movie, I was disgusted," he says. But he adds that he got over it once he saw some of the daily footage, "and I said, 'This kid's still got it!'"

As for that racy nude scene in the preview trailer in which Holmes is shackled to a bed -- strategically covered by a pillow -- Guy jokes, "Well, I know we had to augment the size of the pillow for the trailer."

"Did you have to make it smaller to make me seem more significant, or larger to quell the audience's thirst?" asks Robert wryly.

Adding a saucy element to the epic action-adventure from blockbuster producer Joel Silver, Rachel McAdams plays Robert's love interest in the film, and she reveals, "You know there's romance there, but we're kind of on opposite sides of the law, so it makes being together virtually impossible."

Jude Law also stars opposite Robert as Holmes' trusty sidekick, Dr. Watson, but it's not the first time he's been involved with a Sherlock project, saying, "One of my first jobs was on the Sherlock Holmes TV show in England. I played a stable hand - [moving up in the world] from stable hand to [Dr. Watson]."

Watch ET for more with the stars of 'Sherlock Holmes'!

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