Simmer Down follows Nikki DiMarco as she confronts the owner of a food truck who absentmindedly parked on her and her mother’s regular spot. She tries to be nice, but Callum shows her that he’s nothing but an asshole. What happens next though is a cat-and-mouse rivalry that goes viral, a food truck war, unprecedented sexual tension, the start of a casual relationship, the influence of social media, and more.