"Part of a Long Story" by Agnes Boulton is a hardcover book published by Doubleday in 1958. The book is a biography focusing on the life of Eugene O'Neill, offering insight into the renowned playwright's work and personal journey. Agnes Boulton brings to light the complexities and triumphs of O'Neill's life, making this book a compelling read for fans of biographies and those interested in the life of Eugene O'Neill.