The letter 'K' has a magical effect on the box-office. The myth began with Arjun Hingorani's films and it worked with Rakesh Roshan too. Now the new player is Karan Johar, who is on the threshold of a hat-trick of 'K's this week with 'Kal Ho Naa Ho', preceded by 'Kuch Kuch Hota Hai' and 'Kabhi Khushi Kabhie Gham'. With this success, it wouldn't be presumptuous to assume that quite a few others would also follow suit, given the herd mentality of the film folks.