I haven't seen this film yet; the script is quite a lively piece of entertainment, about a London hit man who gets out of prison and visits Los Angeles to avenge the death of the daughter. There's not much mystery - Wilson goes after Valentine, who was involved... he has a fling with a woman who knew his daughter.
There's a nice bit at the end where Valentine admits he did it because the daughter didn't want him to be a criminal. There's a fantastic bit where Wilson is thrown out of a building, goes in and shoot a bunch of people. Some enjoyable character interplay - Wilson talking about his life, Valentine talking about the sixties, Emma discussing her acting career.
It feels a little on the light side, like it sacks a subplot or a twist or something. It's lively though and has some fantastic character stuff.