It's based on the character created by Sir Arthur Conan Doyle, and set in 1890 London. The approach is campy with action heroes.

Sherlock Holmes (Robert Downey Jr.) and Dr. Watson (Jude Law) are partners in trying to prevent a sixth death of a villain identified as Lord Henry Blackwood (Mark Strong), who appears to use magic in his longterm plans to take control of government. They are assisted by Inspector Lestrade (Eddie Marsan), a less-than-competent policeman. Blackwood appears to return from the dead after being hanged for his crimes and leads Holmes and Watson on a merry chase that includes various unworldly incidents.

Watson's fiancée, Mary Morstan (Kelly Reilly), seems to threaten Holmes' and Watson's relationship. A beautiful criminal who has outwitted Holmes in the past, Irene Adler (Rachel McAdams), becomes involved in the story as she is working for a mysterious employer. Ultimately, a satisfactory resolution is achieved.

At some levels this film provides an entertaining two hours. But it's filled with cinematic tricks, improbable pot twists, and repartee more akin to Batman and Robin. It got a little wearying by the end.

If you like action movies, you may enjoy this one. I prefer my Holmes to be more cerebral.