Akash (Ranbir Kapoor) lives in New York City; he has bankrupted his company and is in need of $12 million for paying the shareholders, but is unable to obtain a loan due to a stock market crash. He decides to jump off the George Washington Bridge. He meets Kiara (Priyanka Chopra), from San Francisco, who is also suicidal after catching her fiancé Kunal (Zayed Khan) cheating on her. Akash and Kiara attempt to kill themselves, but are prevented from doing so by the Coast Guard. Still suicidal, Akash deliberately allows himself to be hit by a car, and Kiara falls on the bridge and breaks her neck. Their suicide attempts are unsuccessful, and they end up in hospital together. When they are discharged, Kiara takes Akash to her apartment because his house has been seized by the bank.

The pair try to kill themselves five times, failing each time. Eventually, they make a pact to end their lives on 31 December 2009. With 20 days left before their deadline, they decide to fulfill their unrealised wishes and begin a journey together. Kiara helps Akash find a date and shares with him how Kunal cheated on her. The next day, Akash cleans Kiara's messy apartment. Though he cannot swim, Akash is forced to fulfil Kiara's wish to swim in the cold Atlantic Ocean. However, at sea Kiara falls overboard and Akash rescues her. Their yacht drifts away, stranding them. As the two slowly succumb to hypothermia, Kiara continues telling her story to Akash. They are rescued again by the Coast Guard officer who intervened on the bridge.

After returning to land, Kiara's depression continues. She attempts to kill herself by drinking bleach and is rushed to hospital. After she is discharged, Akash realises his love for her, and tries everything to make her happy. The two venture to Las Vegas, as Akash has never gone on a holiday, and they end up in bed together. Kiara tells Akash that she still loves Kunal. Akash insists that she move back in with her parents and give Kunal a second chance. Akash moves in with his friend and colleague (Joy Sengupta), and plans to return to India on the night of 31 December to start afresh.

Akash attends the bank settlement and reconciles with several friends with whom he had fallen out, as well as with his estranged father. Meanwhile, Kiara cannot stop thinking about Akash, and on the 31st she realises that she has fallen for him. Kunal discovers this and drops Kiara off at the airport. She reaches the bridge, but finds herself alone, believing she will never see Akash again. Just then he arrives. The pair go out to sea to die. Akash throws a beer bottle with a note in it, which Kiara gets and reads before he proposes to her. Surprised, she accepts, and the couple share a kiss while the Coast Guard rescues them. As the credits roll, Akash and Kiara are shown two years later, married with their baby boy.

The cast is listed below:

• Priyanka Chopra as Kiara
• Ranbir Kapoor as Akash
• Vishal Malhotra as Gaurav
• Joy Sengupta as Deven
• Pooja Kumar as Peshto
• Tanvi Azmi as the Doctor
• Kumar Pallana as the Coast Guard
• Nakul Kamte as Kiara's dad
• Sucheta Khanna as Sapna, Deven's wife
• Zayed Khan as Kunal Nanda (cameo)

Development

After three romantic comedies, Siddharth Anand wanted his next film to be a romance, yet different from the usual films which were being made at the time. Anand felt he had run out of plot ideas, believing he was writing just "another story". His wife Mamta then came up with the core narrative concept about "two suicidal strangers meeting and falling in the love". Anand revealed that this changed his viewpoint, saying: "It was a scene that got me completely excited and we started writing immediately. It's a scene that dictates the story."

Anand then approached novelist Advaita Kala to develop the story into a feature-length script. Although a bit hesitant, she accepted the offer. Intrigued by the premise of the story, Kala started sketching the characters over the next few days, and began writing the script, which she found very different from writing novels. Anand helped her understand the process of writing screenplays and co-wrote with her. Kala wrote the first draft, approaching it like writing a book, and sent it as chapters to Anand, saying: "Writing a screenplay can also be a lonely process like writing a novel, but along the way when others get involved, it becomes a fun collaborative effort."

In an interview with the Deccan Herald, Anand talked about how the American sitcom Friends influenced the film's two characters revealing he wanted viewers to respond to Akash and Kiara in a similar way. He said: "I remember when I watched Friends I wanted to meet and know every character. That's how I want audiences to feel about Ranbir and Priyanka." He also wanted the two to resonate with the audience the way the characters in Dilwale Dulhania Le Jayenge (1995) did. In another interview discussing the film, Anand revealed that he wanted to make it different from his earlier films, aiming for it to be a "subdued romance," which is not sexy. He said: "Everyone is going to be covered up in scarf's and mufflers and over coats and boots. This is a rare instance that you’ll see Indian actors dressed full up without skin show."(sic) In September 2009, it was announced that Sajid Nadiadwala would produce the film as he was highly impressed by the script.

Ranbir Kapoor and Priyanka Chopra were the original choice for the film and their casting was confirmed by Anand in August 2009. After Chopra had starred earlier in Nadiadwala's Mujhse Shaadi Karogi in 2004, both had wanted to work together again, but nothing had materialised. Much later, Nadiadwala reached out to her to discuss a film he was developing with Anand and Kapoor. Chopra met Anand to discuss the script, but the project did not work out. Later when Nadiadwala approached her again with the script of Anjaana Anjaani, Chopra accepted the role. Manish Malhotra designed Chopra's clothes; Mamta Aanand designed Kapoor's. Salim Sulaiman composed the background score, while Rameshwar S. Bhagat edited the film.

Filming

Principal photography began in New York City in late December 2009. The setting of the film required filming in winter during the festive season of Christmas leading up to New Year's Eve. Ravi K. Chandran handled the cinematography, while Sharmishtha Roy handled the film's production design. Filming was done in various locations in New York City, Las Vegas and San Francisco. Anand wanted to capture the distinct flavour of each city.

Anand selected the cities to augment the characters' backgrounds. He chose New York city for Kapoor's character Akash. San Francisco was chosen to depict Chopra's character Kiara as he thought it was "the right backdrop to highlight her life and character". Anand described "Blush", the car driven by Chopra's character, as the film's third character as it is featured extensively. After going through several car options, he chose a vintage red Cadillac, which was later purchased especially for the film as Anand thought the car should represent all of Kiara's attributes. This allowed the art director to modify the car's interior with a lot of detailing to suit Kiara's character.

The ice-skating scenes were filmed at Wollman Rink in Central Park, requiring the rink to close to the public for three consecutive days. Some scenes with the leads were also shot at Cafe Lalo, the same restaurant where When Harry Met Sally (1989) was shot. The film was also shot at the Rockfeller Center. The producers had earlier scouted for a public bridge in India that they could use for four days, but due to the 2008 Mumbai attacks obtaining permission from a local government was difficult. The search ended in Kuala Lumpur, where a scene of Kiara and Akash attempting suicide was shot. The opening suicide attempt sequence was filmed at the Golden Gate Bridge. Several scenes were shot in Nevada, Las Vegas. Additional filming was done in Malaysia and Thailand.

Ahmed Khan choreographed the songs. In June 2010, it was announced that a new song would be shot for the film. Shooting ended in July 2010 after filming for the club track was completed. In September 2010, a promotional video for the remix ballad version of "Tujhe Bula Diya" was shot in Film City, Mumbai.