About Sean O'Reilly Sean O?Reilly is a Stone Arch Books author. Books by Sean O'Reilly The Missing Mummy by (author) Sean O'Reilly illustrated by Arcana Arcana Studio Ages 7 to 9 Grades 2 to 4 Monster Beach by (author) Sean O'Reilly illustrated by Arcana Arcana Studio Ages 7 to 9 Grades 2 to 4 The Scare Fair by (author) Sean O'Reilly illustrated by Arcana Arcana Studio Ages 7 to 9 Grades 2 to 4