Odd Man Out by Sarah Ellis

Kip is the ‘Odd Man Out’ in a household of females. While his mother has gone to Hawaii for her honeymoon, he’s been sent to spend a month in the summer at his grandma’s island home with five girl cousins. Gran’s house has been sold and is about to be torn down so almost anything goes. Kip and his cousins are allowed to demolish the walls, write anywhere, do anything, as long as they don’t tear down bearing walls or are mean to each other. The cousins have fun with beach campfires, swimming and exploring tide pools, but Kip is often overwhelmed by the craziness of his girl cousins and he just has to get away. He escapes to the attic which becomes his sanctuary. There he finds a complicated mystery connected to his father when he was a boy. As Kip explores a thick scrapbook which once belonged to his father, he finds out more and more about him and his strange imagination, and about himself.