Karan (Saif Ali Khan) and Rhea (Rani Mukherjee) can't get along even if their lives depended on it. So when they meet for the 1st time, they are determined to make it their last. But 3 years later, when they meet at her wedding he starts to realise that she may not be half as bad. Too late Karan! 4 years pass and fate brings the two together yet again, but a lot has changed since they last met.