Cross-time Travelers Police Parallel Worlds, March 16, 2001 Reviewer: David Johnson H. Beam Piper's Paratime stories, first published between 1948 and 1965 and culminating in his novel ~Lord Kalvan of Otherwhen~, chronicle the efforts of a human civilization from a parallel world which has discovered the secret of cross-time travel to protect the "Paratime Secret," the very existence of the multitude of parallel worlds. As the Paratime Police protect the Secret they also make it possible for this "First Level" civilization to exploit the parallel worlds, something they have been doing for the past 10,000 years! Naturally, much of the adventure takes place on Fourth Level, Europo-American Sector, Hispano-Columbian Subsector -- our own place in the multiverse. Piper's novel traces the exploits of Calvin Morrison, a Pennsylvania state trooper who is mistakenly transported to a parallel world of musket and pike warfare and a theocracy based upon the secret of gunpowder. Morrison becomes "Lord Kalvan" as he helps a local prince -- and his lovely daughter -- to combat the gunpowder god's minions. While billed as "complete" this compilation, which consists of the Kalvan novel and Piper's stories previously collected in the 1981 anthology ~Paratime~, edited by John F. Carr, omits two other possible Paratime stories, "Genesis" and "Crossroads of Destiny" which appeared in the 1983 anthology ~The Worlds of H. Beam Piper~, also edited by Carr. Two sequels to ~Lord Kalvan of Otherwhen~, 1985's ~Great Kings' War~ by Roland Green and John F. Carr, and ~Kalvan Kingmaker~ by Carr just published in 2001, are also not included. Also recommended by H. Beam Piper: ~Four-Day Planet~ (1961), ~Uller Uprising~ (1952), ~Junkyard Planet~ (aka ~The Cosmic Computer~) (1958), ~Space Viking~ (1962), ~Federation~ (1981), and ~Empire~ (1981). Originally posted at https://www.amazon.com/review/RIGLYLU8JP8LJ/