Easily the most tension film I have watched in years. The story is riveting, dark, and complex. As someone with 32 years in law enforcement, including undercover activity (far sumpler and more short term than what is portrayed in this film), I'll assert this was a masterpiece that definitely had some experienced technical advisors. My wife and I were both transfixes by the journey of both the suspect and the undercover as they slowly and carefully inched toward the revelation of the truth. Not a film I would let any child under 13 watch, possibly even a couple years older. It's a great film, but certainly not easy to watch at many points.