At the start of high school, Piper, Sophie, Isabella and Honor think they will be best friends forever, so they sink a time capsule in the lake with a list of things they want to do before graduation. By senior year, they have gone their separate ways. Piper has turned into the class clown, party girl who never passes up a drink. Sophie pledges to stay a virgin until she is married and has created a purity app. Isabella is the feminist femme fatale who's the editor of a zine. And Honor is the pride and joy of the community. Her dream of being a professional ballerina is taking off. But when tragedy strikes, the former BFFs must reunite, break open the capsule and complete the pre-graduation bucket list.