Two of my friends had recommended me these books for the holidays; so I hitched myself and it took me three days to get to the end of the story; but God it was laborious! These books are a kind of Da Vinci Code in so well. The heroes spend their time on a plane, a train or a boat, from one continent to another (that eventually make your head spin) in search of the keys of a puzzle on a global scale (and well beyond for that matter). The only problem is that Dan Brown alternates chapters where we discover a piece of the puzzle with the chapters where it does not happen much. Conversely, Marc Levy was a chapter with a real discovery for 10 chapters where there's absolutely nothing happening except suites descriptions and dialogues without much interest. One has the impression that the sauce was diluted to make two pounds and only one would have been the case; this is particularly the case for the last third of the first volume and the first half of Book 2 that are particularly annoying. I put 2 stars, but finally I liked the end, and even if it is completely preposterous. I also particularly disliked the style (narration is in the past but the hero "talks" to the present) and the vocabulary is particularly inelegant. Ultimately, it could have been a good novel if the author had merely one volume and had a bit more polished style instead "to blacken the pages of a notebook" as repeated several again the hero, Adrian.