LOOOP LAPETA is the story of a girl in a race against time to save her boyfriend. Savina Borkar aka Savi (Taapsee Pannu) is an athlete based in Goa. She is trained by her father Atul Borkar (K C Shankar) and it is his dream to see her become a successful sportsperson. While running a race, she trips and injures her knee so badly that she can no longer participate in races. She gets depressed and is about to end her life when she bumps into Satyajeet aka Satya (Tahir Raj Bhasin). Both fall in love and move in together. Satya wants to become rich using shortcut methods. He tries his hand at gambling but doesn't get the desired result. He starts working for Victor (Dibyendu Bhattacharya), a gangster cum restaurateur.
Savi, meanwhile, takes up the job of taking care of an octogenarian (Abdul Majid Shaikh). On the day of Savi's birthday, while taking care of the elderly patient, she realizes in his toilet that she is pregnant. She gets high on drugs and this is when Satya calls her. He is in panic and narrates to her that Victor had told him to deliver a parcel to a man and bring cash amounting to Rs. 50 lakhs in return. Victor had given him 80 minutes to complete the job. Satya delivered the package and got the money. While returning to Victor's restaurant in a bus, Satya starts smoking pot with a fellow passenger. The cops enter the bus at a bus stop. Realizing that Satya is smoking a banned substance, they try to nab him. A scared Satya escapes from the bus. After outsmarting the cops, he realizes that he forgot the bag that contains the money in the bus. Hence, he calls Savi and asks for her help. Savi advises him to go to the bus depot where the bus is headed to. Satya does as instructed and even finds the bus.
However, the bag is no longer there. Meanwhile, she runs and meets her father, with whom she has broken all ties after her accident and after she began dating Satya. Savi asks him to pay Rs. 50 lakhs. He refuses straight away. She shows him the middle finger and leaves. She gets into a cab run by a man called Jacob (Sameer Kevin Roy). She asks him to take him to Satya. However, Jacob refuses as he's depressed since his girlfriend Julia (Shreya Dhanwanthary) is getting married to someone else. An angry Savi breaks his side mirror. A cop, David Colaco (Bhupesh Bandekar), witnesses Savi vandalizing Jacob's taxi. He runs behind her.
Meanwhile, with no other option, Satya tries to steal from a jewellery shop called Shree Mamlesh Charan Chaddhaji & Sons Jewellers. It is run by Mamlesh (Rajendra Chawla) who treats his two sons, Appu (Manik Papneja) and Gappu (Raghav Raj Kakker), in an insulting manner. As luck would have it, Appu and Gappu are fed up with daily humiliation. They are also about to loot the jewellery store at the same time. Satya enters the shop and steals money from the locker. As he's about to escape, Appu and Gappu enter. Savi reaches the store and helps Satya escape. At the back alley, Satya and Savi are rejoicing when Mamlesh lands up and shoots Satya dead.
All of a sudden, Savi finds herself back in the toilet with the pregnancy kit in her hand. It takes a while for her to understand that she had gone back in time. She gets a call from Satya, who informs him about the mess. She realizes that she has got one more chance to save Satya's life. What happens next forms the rest of the film.