The movie expertly cuts forth across all four lives. The main thing that impressed me was the varying tension levels in each life. The movie alternates across each life in a round-robin fashion. About 10-15 minutes are devoted for each life. Every time Brad Pitt (the husband of the tourist) life is visited, the tension increases to screaming proportions. The tension level in his case starts high in the beginning and it maintains the high-levels through out. The maid and the 2 boys are shown happy at first and their lives gradually deteriorate over time. The Japanese girl's life simmers in sadness and low tension levels that promises high but ends low key. None of the four parties really did anything wrong. Their terrible situation is not their mistake at all. If at all someone is to be blamed, it is the father of the kids, for giving the kids a gun. But then he gave the gun to help them ward of jackals. At the same time, on the flip side, all of them make teeny weeny mistakes but none of them are uncommon and not all people who make those mistakes get punished like this. I like the 'quirk of fate' aspect this movie investigates. Among the lives pictured, I was most touched by the Deaf/Mute Japanese girl. The way, in such a shot period of time, her plight is shown was commendable. Destiny is an under-rated master controller of life. This movie tells us that in an emphatic fashion.
On a negative note, I think Innaritu has thrashed this concept to death. While Amores Perros was excellent, 21 grams was mediocre and Babel was good without being really brilliant. I can't see him making a similar movie that will tell us what he hasn't yet told yet. We are impressed but we've had enough.