As a lifelong fan of time travel and alternate timeline stories, I first read this yarn when it was serialized (as "Gunpowder God") in ANALOG in 1964. I came across it recently at a university book sale and decided it was time to reread it, and I wasn't disappointed. Calvin Morrison, a Korean War veteran and the son of a minister, is a corporal in the Pennsylvania State Police (an organization for which Piper evidently had a high regard). While preparing to rush a bad guy holed up in a farmhouse, he's sideswiped by a passing Paratime Patrol transtemporal vehicle and gets bounced into an alternate Pennsylvania countryside where the Aryans of India went east instead of west, occupying what did not become China and then crossing the Pacific. Morrison is extremely adaptable -- it apparently takes him only an hour or so to accept what's happened to him and that he's not going back to his own world -- and quickly finds himself "Lord Kalvan," chief advisor and war leader to Ptosphes, Prince of Hostigos. All in all, this is a delightful exercise in military and geopolitical fantasizing . . . though it seems odd that people who get scooped up willy-nilly and dumped in ancient Rome, or wherever, always seem to possess all the political, historical, and technical knowledge to set themselves up nicely. Of course, if the displaced person were an overweight fries-cooker at Burger King, or a Mary Kay saleswoman, there wouldn't be much of a story! This is by far the best (and longest) of Piper's Paratime stories. If you liked Sprague De Camp's _Lest Darkness Fall,_ you'll love this one!