Once every 4 years, the Kingdom held a Selection for the Princes. And on that very day, 35 girls were chosen. And in that group of girls, only 7 can remain. Unless of course, the Princes decide to not get married. But that's an unlikely case. [ this story is based on " The Selection " by Keira Cass. By no means am I stealing her story, I am simply using her idea. ]