The great music score, cinematography and acting makes it good, if not great. Great is tough to reach, and much like the balloon in the story it goes too high and slips out of our grasp. Ian Mcewan has written excellent novels, Atonement being a highlight, but this one just tries to achieve too much and doesn't have the meat in the characters to back it up. However, it does make you think, and sometimes squirm with its observations and insights. I saw this as more an existentialist drama than a thriller, though the Hollywood crazy stalker plot point was probably enlarged to keep it entertaining, but it was the quieter and more introspective moments that caught my interest. Daniel Craig does a terrific job of playing a man obsessed with looking for a seemingly impossible to find answer to the mysteries of the randomness of life and death. Rhys Ifans plays the truly unique character and his creepy viewpoint makes you shift in your seat. It's consistently engaging but never a masterpiece, it's takes the loud and angry showdown rather than the quiet thinking that made it work to start. Will still make you never look at a hot air balloon the same way again.