Fans of Dan Brown's novels about symbologist Robert Langdon solving religious puzzles should like Angels & Demons. Fans of narrative storytelling may feel differently. Based on Brown's less popular, but first, Langdon novel, this was all they had left for a sequel to the The Da Vinci Code.
This time, someone has threatened to murder four cardinals and set off a stolen antimatter bomb. Luckily, the key to the villain's whereabouts lies in a trail of clues that begins in the Vatican's historical archives. As Langdon solves the clues to save the day, he also teaches the audience about the Illuminati and popes of papals past (soon to be a spinoff starring Matthew McConaughey.)
Angels & Demons is presumably as faithful to its source material as the Da Vinci film was. The only obvious adaptation are two passages of dialogue specifying that these events take place after Langdon's first religious adventure. It doesn't really impact the story to make this a sequel rather than a prequel, but they did.
The problem with the story, as with Da Vinci, comes from the source material. As interesting as the history may be, Dan Brown is not crafting compelling drama or suspenseful mysteries. The characters just go from place to place talking about history. These stories make Indiana Jones and the Kingdom of the Crystal Skull look like Raiders of the Lost Ark.
A slight advantage Angels has is that the action picks up after an hour. That's right, you only have to wait nearly half the movie to be excited. Langdon has to escape some tight scrapes like a regular old action hero. There's even a big explosion. So by being more like everything else, Angels & Demons rises slightly above boredom and into plain old mediocrity.
Don't expect the series to improve, though. It is now firmly established as a hit franchise, so the filmmakers would be wise to continue telling the same type of story. If Dan Brown can write another talky art history lecture, then Ron Howard and Tom Hanks can film it for all the fans.