"Diana and Leo," the sequel to "The Alchymist and The Silurist," limns the life of Gabrielle Jogand-Pages, a 19th-century Parisian who wrote and published lurid stories involving an American girl named Diana Vaughan, who sought to prove her familial relationship to the 17th-century Welsh scientist Thomas Vaughan, The Alchymist and twin brother of The Silurist, the poet Henry Vaughan, both of whom were distant kinsmen of author James Vaughan. Now available on Amazon's Kindle.