In 1997 teenager Sophie White and her three girlfriends decide they want to lose their virginity before summer is over. Roping in her childhood buddy Gareth and his mates, Sophie holds a party to get the deed over and done with, but the night doesn't end as planned. Twenty years later, the group are brought back together when Gareth is killed in a car accident and Sophie begins receiving threatening messages. It seems the party wasn't as innocent as everyone thought and now someone wants payback.