The film, being produced by Pritish Nandy Productions, will be directed by debutant Saket Chowdhary (who assisted Kunal Kohli in Hum Tum). Shooting is slated to start on October 21.
"This one is straight off in the league of the Doris Day-Rock Hudson and Meg Ryan-Tom Hanks romantic comedies. It's the best-written script I've come across in the genre," says Rahul.
Is he looking forward to working with Mallika? "Of course I am! I think she's incredibly spirited."
Rahul was in Canada last month to attend the Toronto film festival where his film Kaal Purush was screened.
"Sensitive, contemplative and gentle... That's how audiences found my film to be. It was a very sobering and uplifting experience. There were just Buddhadeb Dasgupta (the director) and I."
Leading lady Sameera Reddy was at the Rohtang Pass in Himachal shooting with Vivek Oberoi, Sunny Deol and Jackie Shroff for Sachin Bajaj's film.
"We had two screenings Sep 15 and 17 in 550- and 350-seater theatres - both filled to capacity. They loved the film 'Memories in the Mist'. They unanimously found it simple and true."
This was Rahul's fifth visit to the film festival.
He still remembers going there in 1995 for the first time with Dev Benegal's English August.
"That was in English while Kaal Purush is in Bengali... but it doesn't make a difference. Deepa Mehta's Water is in Hindi and yet audiences in Toronto loved it. Language is no longer a barrier."
Rahul plans to do another Bengali film with Buddhadeb Dasgupta. "Kaal Purush put me in touch with emotions within me that I never knew existed."