Paul Prye may make his living as professor of urban history at Columbia, but at heart he is mad about crime. So is his wife Alice, art history prof at NYU and wild about Agatha Christie. In 1988, they go to London to celebrate a most curious centenary: Jack the Ripper's bloody safari through the city's dark bypaths and dead ends. Prye retraces the maniac's sinister progress in the company of others similarly smitten, and as marvelous luck would have it, one of their group is murdered. Could it have been an accident, as others insist? Prye knows better (and he is seldom, if ever, wrong). The Yard agrees. Somewhere in the thickets lurks a new Ripper fixated on replicating his master's bloodbath. But Prye's analytic intelligence and Alice's intuitive antennae eventually end the nightmare in this pleasant and clever, if not particularly suspenseful, little nocturnal excursion. (March 31).