In Happy Death Day, Jessica Rothe’s Tree Gelbman is going about her birthday generally being a terrible person when she is killed on her way to a party.
The candle on the poster rests on a red velvet cupcake, and if you’ve seen the first film, you know that the cupcake has major significance.
Over the course of the film, she dies and dies again, each time gathering information to try and discover the identity of her killer, stop him, survive and break the loop.