The second installment of the series. Madrid, 1614. Isidoro Montemayor plunges into another investigation when the Marquis of Hornacho hires him to solve the murder of Gonzalo Escondrillo. His corpse was found in the library with his left temple pierced by a horn that belonged to the cabinet of wonders, a room filled with all sort of marvels. But was Gonzalo just in the wrong place at the wrong time? Or did someone want him dead?