Alison gets several messages from Charles telling her to meet him at the prom .
After Rosewood High bans the Liars and Alison from attending their prom and graduation , the girls ' mothers offer to hold a substitute prom in Spencer 's barn .
Alison gets several messages from Charles telling Alison to meet him at the prom .
After Rosewood High bans the Liars and Alison from attending their prom and graduation , the girls ' mothers offer to hold a substitute prom in Spencer 's barn .