Second grader Alfie Jakes knows that when it comes to some friendships, one day you're in, and the next you're out. When Alfie's former best friend, Lulu, announces that she's hosting the best sleepover ever--and that she's only allowed to invite six girls--Alfie desperately wants to go but is not sure she'll be one of the lucky few. Lulu's classmates are doing all they can to win her favor, a task that often ends in tears. Can Alfie convince her used-to-be best friend that a party is better when everyone is invited--or will she get herself uninvited instead?