The Invitation

It arrives on crisp ivory paper, printed in elegant gold writing- an invitation to the social event of the year: Cass Rockham's annual Autumn party. But why has Cass invited Sarah and her four friends? They aren't rich or popular like the rest of Cass' Crowd. Is there some darker meaning behind the invitation? Soon, Sarah discovers that she and her friends are in grave danger. they havent been invited to a party, they've been invited.... to die.