Synopsis: O2 revolves around a bunch of people who get trapped in a landslide while they are on their way from Coimbatore to Cochin. Parvathy is a single mom to 8-year-old Veera, who suffers from cystic fibrosis. This means that Veera can breathe properly with the help of an oxygen cylinder. Similarly, there’s a couple waiting to elope, an en-MLA, a corrupt police officer, a bus driver and a few others.