The House On The Strand by Daphne Du Maurier
FROM THE BESTSELLING WRITER OF REBECCA
The House on the Strand is prime du Maurier. . . . She holds her characters close to reality; the past she creates is valid, and her skill in finessing the time shifts is enough to make one want to try a little of the brew himself - New York Times
When Dick Young's friend, Professor Magnus Lane, offers him an escape from his troubles in the form of a new drug, Dick finds himself transported to fourteenth-century Cornwall. There, in the manor of Tywardreath, the domain of Sir Henry Champerhoune, he witnesses intrigue, adultery and murder.
The more time Dick spends consumed in the past, the more he withdraws from the modern world. With each dose of the drug, his body and mind become addicted to this otherworld, and his attempts to change history bring terror to the present and put his own life in jeopardy.