Coincidence) is a 2017 Indian Hindi-language neo-noir mystery thriller film directed by Abhay Chopra, written by Chopra, Shreyas Jain and Nikhil Mehrotra, and produced by Gauri Khan and Shah Rukh Khan under Red Chillies Entertainment in association with Renu Ravi Chopra under B. R. Studios and Hiroo Yash Johar and Karan Johar under Dharma Productions.

On the launch of his third book in Mumbai, he finds his publisher wife Katherine dead in their hotel room.

As the police give chase, his car overturns and he escapes with injuries, taking shelter in a nearby apartment.

Vikram whipped out a knife and overpowered her, and began searching for documents at Shekhar's desk when she turned a visiting Chirag away, with whom she confessed of having an extramarital affair.

The police eventually conclude that Vikram's account is true and Maya and Chirag had killed Shekhar when he confronted them with the photos.

At home, Dev is reading Vikram's second book when his wife Meera spoils that the protagonist dies of drug overdose.

Dev rushes to the forensic doctor to check if Vikram's wife could have died from an overdose of the medicine she had been taking for her heart.

They discover that the capsules had been tampered with and the dose was made three times higher than normal, which caused Katherine's fatal heart attack.

He partially burnt them and threw them in the trash, banking on the conviction that the police would find the ominously burnt, adulterous pictures, creating a convincing story to dupe the police, which would then insinuate the inquisitory suspicion that it was Maya, in conjunction with Chirag who had orchestrated the murder of her husband Shekhar in order to conceal her affair.

Co-produced by Red Chillies Entertainment, B. R. Studios and Dharma Productions, Ittefaq released on 3 November.

While Sidharth Malhotra reprised Khanna's character, Nanda's role is essayed by Sonakshi Sinha.

[3] But before its release they came out with a digital media campaign, requesting viewers not to disclose the culprit after watching the film.

Rather than using traditional and costly marketing techniques (reality show promotion, media interviews and city tours), the producers decided to focus on television, radio and print advertising.

Hollywood's Thor: Ragnarok of the popular Marvel Cinematic Universe, which recorded strong opening collection, was released concurrently with the film thus affecting its business.

[6][16] The theme song ''Ittefaq Se'' was recreated by Tanishk Bagchi from the song "Raat Baaki Baat Baaki" from the film Namak Halal (1982), originally composed by Bappi Lahiri and sung by Asha Bhosle, Shashi Kapoor and Lahiri.