There's certainly much intrigue in "Sherlock Holmes: A Game of Shadows," but one thing that isn't a mystery is that everyone involved in the film seems to be genuinely having a jolly good time, despite sinister plots that are happening all around them.

Director Guy Ritchie continues to put his stamp on the Robert Downey Jr. star vehicle by turning "Sherlock" on its ear. Sir Arthur Conan Doyle's cerebral sleuth gets a shot of adrenaline (literally in this sequel) with Ritchie behind the camera and Downey putting his own sly spin on the character. Like the 2009 "Sherlock Holmes," this is a big-budget modern action movie, no doubt about it, despite its backdrop of 19th century London. The two worlds collide beautifully, creating a cinematic dream world in which the man on a mission, Holmes, tracks clues in England, France, Germany and Switzerland.

Screenwriters Kieran and Michele Mulroney -- brother and sister-in-law to actor Dermot Mulroney -- pluck from Conan Doyle's story "The Final Problem" for their nemesis to add excitement to the movie franchise. This time Holmes matches wits with a most challenging adversary, Professor James Moriarity (the wonderfully sneering Jared "Mad Men" Harris), an evil genius whose skill set may put to the test those of the usually untouchable Holmes. Readers will also recognize Mycroft Holmes, Sherlock's older brother, played to the eccentric hilt by English treasure, Stephen Fry.

Adding even more fun to "Sherlock Holmes 2" is another new character, Gypsy fortune teller, Sim. It's the first English speaking role for Swedish actress Noomi Rapace, the original "Girl With the Dragon Tattoo." She has her work cut out for her and holds her own partnered with Downey and Jude Law, who returns as Dr. Watson, in many of the high-octane action sequences.

Those looking for a faithful adaptation of "Sherlock Holmes" will believe that Conan Doyle is turning over in his grave watching Downey in a skin tight jumpsuit, dressed in drag and brawling bare handed ? things we'd never imagine the Burberry wearing, pipe-smoking Detective Holmes of lore to do. Yet, that's truly what brings the new Holmes to Technicolor life, re-invented and ratcheted up for contemporary movie audiences.

Downey has said his desire is to play the Holmes character until he's old and gray. After seeing "Shadows," it's definitely not a mystery as to why.