As in various thrillers (like Bourne Identity), the plot is centered around the amnesia of the protagonist: he tries to find out who he was, who killed his wife and son, who are the people that come up to him after he wakes from his coma, what are their real motivations, and what dark secret is behind it all.
I had only three gripes: 1) Lazar's flashbacks allow us to suspect the identity of the killer too early on; 2) in the action sequences his antagonists seem rather incompetent; 3) Kojo puts on a solid performance, but sometimes Lazar just stares at people with a deadpan expression. Very Serbian no doubt, but takes some getting used to.
The movie kept my interest throughout, and the dark secret revealed at the end is indeed dark. The conclusion is powerful, and reaches beyond a personal tragedy.
Overall a good action thriller, darker than Bourne's Identity, and superior to most Hollywood fare.