The gadget had a ghost

A physics professor at the American College in Istanbul, Dave Coglan, is visited by Lieutenant Ghalil of the Istanbul Police and M. Duval, a French scholar. After much deliberation, they query if, by any chance, he has been visiting the 13th Century. At first, Coglan does not take them seriously. Along with Ghalil and Duval, however, is a 700-year-old book with notations in English that includes his name and address. Further, the book has Coghlan's fingerprints and refers to an address and a reference to killing someone. How is it that the 700-year-old book can contain his fingerprints? Is he a suspect in a murder yet to happen? The Gadget Had A Ghost is a different type of science fiction story and mystery