Book 1 in the series. Bound by limits dictated by society, Art Historian Nicolas Halstead lived a guarded life until a tempest in the form of Elenora Schwaab blew into his world. At first Nicolas can't decide if the audacious American is simply mad or plotting blackmail for not only does she declare knowledge of his homosexuality, she offers him a marriage proposal. After Ellie tells him of a previously unknown work of Leonardo da Vinci, a book of erotic love poems and sketches dedicated to the artist's long-time lover Salai, Nicolas joins her in a race to save the book from destruction. Along the way they encounter Historian Luca Franco and discover a comfortable compatibility that comes to redefine their long-held notions of love. The trio embarks on an adventure filled with sensual discovery, intrigue, and danger. Little do they know Leonardo da Vinci's book is far more than meets the eye.