Tell No One

I saw this intense French thriller, Tell No One, the other night with my mom. It's very good, very tense and engaging and there is something just imminently watchable about the French. There seemed, however, to be a few holes in the plot; at least it was kind of confusing at the end and I'm not sure if I thoroughly understood it. It's about a man whose wife is killed and years later starts sending him emails and people are out to get him...