One thing that can be said for sure about Bollywood superstar Amitabh Bachchan's films with Rani Mukherji is that they project the actors in very unusual, exceedingly unconventional combinations.
In Sanjay Leela Bhansali's Black they played the amazingly unorthodox teacher and pupil. And in Karan Johar's Kabhi Alvida Naa Kehna Big B was the philandering Sexy Sam who tells his daughter-in-law to leave his son, so he can find love.
Now in Ravi Chopra's just released Baabul, Big B and Rani play the protagonists, a father-in-law determined to get his widowed daughter-in-law remarried.
So pivotal are the two characters that Hema Malini, who plays Big B's wife, confesses she has relatively little to do.
Speaking on his acutely striking bond with Rani, Big B told IANS: "We've been cast in very unusual roles in Black. And then in KANK we were a very different kind of father-in-law and daughter-in-law.
"Now we play another very different and unusual father-in-law and daughter-in-law in Baabul. I guess we're lucky to have our acting talents being tested in such unusual ways. I'm very fortunate to get such unusual opportunities.
"Rani is a terrific co-star and it's a pleasure to work with her. All of us - Jaya, Abhishek and I - are very fond of her."
He recalls Rani's concern for his health on the sets. "She's a very caring girl. And a thorough professional on camera."
Big B is hoping Baabul would have the same social impact as Chopra's earlier Baghban.
"Though it has in-sync sound, it needed some dubbing, I think it has turned out to be a film that reclaims many of our basic values like Vivah, which I thought was a very sweet film.
"It just took me back to the days of innocence when romance was about exchanging looks. Baabul is also a film that's embedded in our ethos and culture, though the issue here (widow rehabilitation) is far more serious."
Big B is on the verge of completing Balkrishnan's Cheeni Kam with Tabu.
"Balki wants to do another film with me. I've Bhootnath for producer Ravi Chopra. Then Abhishek and I will be doing Ram Gopal Varma's Sarkar 2. Then I also have films with Rakeysh Mehra and Shojeet Sarkar."
But right now his focus is on Baabul.
"The interesting thing about it is that the seeds of its plot were sown in 'Sholay' years ago. The relationship Rani shares with me does have similarities to what Jaya shared with Sanjeev Kumar in Sholay."