"I came across this book at auction as part of a larger lot I purchased on speculation. The damage renders it useless to me, but a name inside it led me to believe it might be of interest to you or your family...."

Simon Watson, a young librarian, lives alone in a house that is slowly crumbling toward the Long Island Sound. His parents are long dead. His mother, a circus mermaid who made her living by holding her breath, drowned in the very water his house overlooks. His younger sister, Enola, ran off to join the circus six years ago.

One June day, an old book arrives on Simon's doorstep. Fragile and water damaged, the book is a log from the owner of a traveling carnival in the 1700s, who reports strange and magical things-including the drowning death of a circus mermaid. Since then, generations of "mermaids" in Simon's family have drowned-always on July 24, which is only weeks away.

As his friend Alice looks on with alarm, Simon becomes increasingly worried about his sister. Could there be a curse on Simon's family? What does it have to do with the book, and can he stop it in time to save Enola?

"The Book of Speculation" is Erika Swyler's gorgeous and moving debut, a wondrous novel about the power of books, family, and magic.