Maybe I am not the right person to review movies as I rarely look at things like the lighting or the gaps in the plot (as long as they're not too obvious) etc. I just take the movie at face value and look at whether I enjoyed the movie or not and I really enjoyed Trap.
In retrospect I can think of a number of things that would, in my opinion, improve the movie but I don't think M Night Shayamalan is going to consult me on his future films anytime soon.
Basically, the police organize a major music concert with the aim of catching a serial killer, dubbed the Butcher, who they know is going to be going to the concert. The draw card is a popular singer with a massive teenage following.
Josh Hartnett is very good at the outwardly normal devoted dad with a very dark side and much of the first half of the movie concentrates on his efforts to escape the ring of police surrounding the venue without being caught.
To comment on the plot any further would spoil the movie but it's obvious that the movie is designed to showcase Shayamalan's highly talented daughter who takes the part of singer Lady Raven, who also wrote and performed most of the songs.
I have seen better movies that I have enjoyed more but, for me, Trap was a pleasant way to pass today's cold, wet afternoon.