Keira Knightley gives a really great performance and stands out the most amongst the cast. Sam Worthington gives a great performance too and proves he's not as bad people make him out to be. Guillaume Canet is pretty good too. Eva Mendes is, well, "meh". She's not as terrible as she has been in most films but that does'nt mean she's a whole lot better. She's still clearly the weak link of that cast. She's not very good, but she's not very bad either. Just "meh". You also get a great supporting cast, including a nearly show stealing Griffin Dunne. Worthington and Knightley have great chemistry and I bought into the fact that they cared about each other, even when tempted to cheat. Canet and Knightley have really good chemistry and made me believe their characters really have this strong bond built up from many years. The chemistry between Mendes and Worthington is pretty bad. Awful even. There's no chemistry whatsoever and I never believe either was truly attracted to each other. The film suffers mostly from cliches and it's not hard to figure out how it's gonna end up. That isn't to say I was'nt interested though. I cared and was interested in the story, the characters, and which party, if either, will cheat on the other. That brings me to my biggest complaint...I hated the fact that Knightley ended up being faithful and Worthington ended up cheating. It pisses me off more that this was written by a woman because the end comes across as "Men always cheat on women and it's easier for women to stay faithful" or "Women cheat emotionally while men cheated physically" which, I'm sorry, but that's the dumbest thing anyone has ever told me. Women are just as likely to cheat on women then men. The way it plays out in the film is Knightley and Canet have all of these meaningful conversations and with the past they've shared, a fire is rekindled in their relationship. Passion comes back to the surface and it would be reasonable if it went as far as them sleeping together. With Worthington, all it basically takes is Mendes to shove her tits and ass in his face before he caves in thinking "Much...touch...boobies!" or something along that. I think this presents men in a negative light and it just irritates me. But, I digress. The more I discuss it, it manages to piss me off even further. Other than these flaws, I think this is a well acted drama that keeps you interesting until it ends and leaves kinda a sour taste in your mouth. It would have been better if played in a straighter, more realistic approach instead of portraying men as male chauvenist pigs.