Ritchie has never worked on a scale anything approaching this before and, while some of the directorial affectations are distracting, he keeps the action humming.

Challenged by Downey’s energy, Jude Law, who often seems aimless in his movies, comes fully up to speed. He’s virile and quick-witted, and his Watson, if not Holmes’s equal in brainpower, comes close to him in daring. Their repartee evokes the banter of lovers in a screwball comedy; they flirt outrageously but chastely.

Sherlock Holmes is an odd amalgam, a top-heavy light entertainment that keeps throwing things at you and doesn't seem too concerned with whether they stick.

The reason Sherlock Holmes fails at least as often as it succeeds is because more effort and attention was lavished upon the concept than upon the script. Given a worthy story, Downey's Holmes might have been memorable. Here, he's an interesting character in search of a worthwhile story.

A fun, action-packed reintroduction to Conan Doyle's classic characters. Part Two should provide more in the way of scope.