In this film we learn various lessons, including the inadvisability of picking a fight with people who have a munitions plant, and the inadvisability of letting Professor Moriarty provide your tea. Minor spoiler alert. I'm not certain Irene Adler is actually dead, and I wonder if the French police of the 1890s would not have been capable of distinguishing death by gunshot from death by bomb blast … little niggles like that kept popping up throughout the movie, but I didn't care. It was too much fun watching Holmes ruin Watson's honeymoon, then generally misbehave across Europe. Plus Stephen Fry was hilariously fun as Mycroft, especially in the at-home scene between him and the new Mrs. Watson.
The whole thing was a slam-bang fest of nigh epic proportions, with loads of period piece fun and games for the Victoriana and steampunk fans among us. Much as with Mission Impossible: Ghost Protocol [ imdb ], the plot doesn't merit much if any intelligent interrogation. It's simply meant to be watched and enjoyed.