Lest Darkness Fall

"Martin Padway was a smart enough young man, with a scientific education, but no universal genius. He had the misfortune to be dropped back suddenly into a former time, and a very alarming time at that -- sixth-century Rome, when the Goths ruled Italy and civilization in the West was collapsing. To make a living, and to try to shore up civilization, Padway undertook to introduce inventions ... . Some worked and some didn't ..."--Jacket, back inside flap.