A humanoid alien (Aamir Khan) lands on Earth naked on a research mission in Rajasthan, but is stranded when the remote control of his spaceship is stolen. He manages to get the thief’s cassette recorder, a Panasonic RQ-565D. On the same day in Bruges, Jaggu (Anushka Sharma) meets Sarfaraz (Sushant Singh Rajput) and falls in love with him. Jaggu’s father (Parikshit Sahni) objects to their relationship because Sarfaraz is a Pakistani Muslim, while Jaggu is a Hindu. He consults godman Tapasvi Maharaj (Saurabh Shukla) who predicts that Sarfaraz will betray Jaggu. Determined to prove them wrong, Jaggu proposes to Sarfaraz, who accepts. She is heartbroken at the wedding chapel when she receives a letter calling off the marriage due to their cultural differences.
Jaggu returns to India and becomes a TV reporter. She meets the alien and is intrigued to see him distribute leaflets about the “missing” Gods. She saves him when he attempts to take money from a collection box, earning his trust.
The alien tells her that he is a research scientist from another planet. His people know nothing about dressing, religion or verbal communication. They transfer ideas by holding hands. The alien learned to fit in among humans by wearing clothes and using money stolen from couples having sex in “dancing cars”.
In the flashback, after being accidentally hit by a truck, the alien is befriended by bandmaster Bhairon Singh (Sanjay Dutt), who takes him along with his troop. The alien attempts to learn to communicate by grabbing peoples’ hands but people chase him away, believing him to be a pervert. Bhairon takes him to a brothel, where the alien holds a prostitute’s (Reema Debnath) hand for six hours and thus learns the Bhojpuri language.
Bhairon has a conversation with the alien, and suggests that the thief may be in Delhi. The alien leaves for Delhi. Due to his strange behavior, the people assume he is drunk and call him “PK” (pee-kay, Hindi for “drunk”). People tell him that only “God” can help him find his remote. PK sincerely practices every Indian religion attempting to find “God”, to no avail. He later discovers that Tapasvi has his remote, who claims it was a gift from God, and refuses to return the remote. Jaggu promises PK that she will recover his remote and he can go back home.