Ex-Special Operations Executive agent Duncan Forrester has returned from the war and is back at his Oxford college as a junior Ancient History Fellow. But his peace is shattered when a much-disliked Fellow is found murdered in the quad. Forrester is not convinced of the principal suspect's guilt and, on the hunt for the true killer, he finds himself plunged into a mystery involving lost Viking sagas, Satanic rituals and wartime espionage.