Ryan Reynolds and Rachel Weisz in Definitely, Maybe Andrew Schwartz/Courtesy of Universal

The clapboard shows that scene #78c is about to start filming. It is Rachel Weisz's last day on the set of Definitely, Maybe, a romantic comedy framed by the present but set predominantly against the political landscape of the 1990s. Weisz and co-star Ryan Reynolds slow dance as romantic jazz floats across the room. The two gaze into each other's eyes, laugh and hug. Swaying to the music, they join hands and kiss. Reynolds twirls her by the hand and dips her so deeply that her head falls back. He fumbles and almost drops her. The director steps onto the set and the two crumple into laughter.

After a couple more takes, Weisz hugs her co-star and gives director Adam Brooks a peck on the cheek. "That's a wrap on Rachel," Brooks announces. The scene, filmed in the living room of a Greenwich Village brownstone in New York City, is to be part of a montage of several romantic moments shared by the two. "He's a good dancer," says Weisz of Reynolds as she takes a seat after the scene. "I just asked him to dip me, and he caught me. He is very, very strong." Reynolds later downplays his dancing abilities, commenting that "most people say they have two left feet. It is like I have no feet. It is just like I am a quivering torso on the ground." An actor's last day on set can be a mixture of relief and nostalgia. Weisz is saddened: "It's always sad to say goodbye. But Adam, the director, lives in New York so I will see him again. [As] actors, we're traveling like a circus. We will meet in another town and at another time."

While this is the exit point from the set for Weisz, at least another two weeks of shooting remain for the rest of the cast. Definitely, Maybe has been a labor of love for Brooks who last directed Cameron Diaz in an adaptation of the Jennifer Egan novel The Invisible Circus. "I had just finished [writing] two movies — Wimbledon and Bridget Jones — with Working Title who are producing this movie," Brooks recalls. "They wanted me to write and direct a movie for Working Title. And for me, from the start, the idea was to do something different and not as generic in terms of romantic comedy… I wanted to make a love story that took place over years. I feel that there used to be a lot of movies that took place over a long period of time and there is something really delicious about it when it works. For the audience, there is something so great to watch someone change over the years. And I always wanted to make a movie about a young man who comes to the big city and what happens."

Ryan Reynolds in Definitely, Maybe Andrew Schwartz/Courtesy of Universal

Brooks' resulting screenplay is the story of Will Hayes (Reynolds), a soon-to-be-divorced father in his thirties, whose 10-year-old daughter Maya (Abigail Breslin) becomes fixated on learning more about his life before he got married. Having had an introductory class about the birds and the bees at school, she begins to question how her parents met and how they fell in love. But Maya is too precociously astute to be misled with a sugarcoated fable and pushes to learn more about Will's past loves. Will agrees to tell all to Maya but — perhaps to distance his emotions — he changes the names of the three women that occupied his world for over ten years and so keeps Maya guessing as to which of the women is her mother in his narrative. "I keep saying it is sort of like a romantic whodunit and that's unusual," says Reynolds. "That is why I wanted to do [this film]. I have done a romantic comedy before where you know pretty early on where it is going and how it is going to end. And with every page I turned of the script, I had no idea how it was going to turn out, how it was going to play out, who Will was going to end up with, how the daughter is going to handle this. It is really interesting. And I think that for me was the main draw. It is a movie I really I want to see as opposed to just do." Weisz concurs that it was Definitely, Maybe's not-so-run-of-the-mill premise that attracted her to the role. She describes the script of this film as bearing a similarity to About A Boy (in which she starred opposite British heartthrob Hugh Grant) in that both films are a little "off-center" because "it is not really boy-meets-girl-and-live-happily-ever-after." With Definitely, Maybe "it is boy has met the girl [and] they have lived happily ever after. They have had a daughter and now they are divorced and the daughter is trying to guess from the stories of the 90's who is her Mum — like a romantic whodunit."