Guy Ritchie reclaims his cool director tag with “Sherlock Holmes,” which, just like his 1998 directorial feature film debut, “Lock, Stock and Two Smoking Barrels,” entertains from fade in to closing credits.

For starters, one need not be familiar with Sherlock Holmes, the fictional detective created by Scottish author and physician Sir Arthur Conan Doyle, or his exploits in the four novels and 56 short stories published from the late 19th to early 20th centuries.

Ritchie’s film is solely based on the Sherlock Holmes character that actor Robert Downey Jr. brings to life on screen as brainy (he figures things out through keen observation and vast experience), brawny (he beats up bigger men), and bohemian (he scoffs at conventions).

It also explores Holmes’ relationship with his partner-in-crime, Dr. John Watson (Jude Law), and features Irene Adler (Rachel McAdams), who’s one of the few women mentioned in Doyle’s literary works but the only one who has impressed the cunning sleuth.

In the process of unraveling the secrets of dark arts-practicing serial killer Lord Henry Blackwood (Mark Strong), Holmes – with the sometimes unwilling Watson and the dubious Adler in the latter part – gets into a series of perilous exploits that he impressively survives.

At the same time, Holmes broods over Watson’s decision to move out of their shared residence to establish his own business and marry his fiancée, Mary (Kelly Reilly). He gets on the couple’s nerves but remains beloved in the end.

Downey and Law are gifted actors whose individual scenes delight as their great chemistry charms even more. The bromance between their characters comes off as cool rather than a turn off.

And though director Ritchie is not seen onscreen except for a sketch in the end credits, his inspired enthusiasm is felt all over the movie.  There’s never a dull moment in “Sherlock Holmes” and it doesn’t have to mystify you for a second screening.