The subject gives pretty much idea on why I am giving my review.
I read the novel by Priest and watched Unknown. I have to say this. I like Unknown better purely because it gives insights in to their relationship. No they are not related. Qian adopts Yuan in to his family so that he can go to school. Yuan and Qian's relationship evolves from where it was to something else. I personally think Yuan is so dedicated and attached to Qian that he subconsciously becomes someone who Qian needs in his life.
For those who find the story unrealistic- I can assure you the situation Qian is in where he has to support his family is not unrealistic. It is seen in most of the asian countries that lack resources to support their large populations.
For those who are contemplating to watch or not watch: Unknown is a masterpiece from cast to story telling. Its beautiful. If you are tolerating the nonsense Thai and some Japanese BLS, loved stay with me - you will love this.
Don't get sidetracked by reviewers who have their own reasons to bring this down.