Karen Joy Fowler has been named the winner of the 2014 PEN/Faulkner Award for her 2013 novel, We Are All Completely Beside Ourselves. The book, about a unique sibling relationship and resulting family drama, was both critically acclaimed and a bestseller. Fowler will receive a $15,000 award.

The other nominees included two story collections  (Joan Silber’s Fools and Valerie Trueblood’s Search Party) and two somewhat experimental novels (Daniel Alarcon’s At Night We Walk in Circles and Percival Everett’s Percival Everett by Virgil Russell).

This year’s judges were novelists Madison Smartt Bell, Manuel Muñoz and Achy Obejas. The PEN/Faulkner website states that they considered 430 novels and short story collections. In a statement announcing the award, Muñoz said, “Fowler captures an altogether new dimension of the meaning — and heartbreak — of family dynamics.”

The winning novel is Fowler’s sixth in a wide-ranging body of work. She is perhaps best known for The Jane Austen Book Club (2004), her most accessible novel. Her 2001 novel, Sister Noon, was nominated for the PEN/Faulkner award in 2001. Fowler has won a Nebula Award, a Shirley Jackson Award and a World Fantasy Award.

The awards ceremony will take place on May 10 at the Folger Library in Washington, D.C.