a '4' only due to the brilliant (Vincent Lindon as Marc, & the equally brilliant Emmanuelle Devos as Agnès) performances in this pretty much 2- person movie. F.Tabouring's above review was excellent, but he seems to miss the most obvious & real point of the movie, which is, quite simply, ridiculous. the premise is excellent, & the movie begins & continues halfway excellently, unfortunately Emmanuel Carrère, the novelist, screenplay & director has no idea what to do from midway to the end. i did not read the novel, but if this is a faithful adaption, then i can only assume the book is as convoluted as the subsequent movie. it is not anywhere near an accurate picture of an individual's fall into insanity; it is not thought-provoking; it is not Hitchcockian in any way; & turns into a farce when the main character either physically or unconsciously supposedly travels to Hong Kong, where he repeatedly rides the ferry between Hong Kong-to-Kowloon "as if" searching for "something"? the ending scenes are equally ridiculous, as well as not thought out, & reminds me of a very young, untalented, unsophisticated director, who "thinks" he is an artist.<br /><br />i say unfortunately in my summary line above because this could have been a brilliant story of loss of identity, & subsequent fall into insanity, & told in such a way as to not have any neat conclusions, but carried the viewer along for the ride. this movie attempts to challenge the viewer, but seems to have forgotten how to tell a story. even the insane have moments of clarity, which this movie clouds by being obtuse & simplistic.<br /><br />it's a shame to have wasted two brilliant actors & their brilliant performances with such a terrible script, & by association, an amateurish & clumsy interpretation by the director/novelist, proving that a novelist should not write the screenplay, & not direct the finished product.