Reading order
| # | Title | Published | Author | Buy on Amazon |
|---|---|---|---|---|
| 1 | Lord Kalvan of Otherwhen | 1965 | Henry H. Beam Piper | Buy |
| 2 | Great King’s War | 1985 | Henry H. Beam Piper | N/A |
| 3 | Great Kings’ War | 1985 | Henry H. Beam Piper | Buy |
| 4 | Kalvan Kingmaker | 2000 | Henry H. Beam Piper | Buy |
| 5 | The Fireseed Wars | 2010 | Henry H. Beam Piper | Buy |
| 6 | Gunpowder God | 2012 | Henry H. Beam Piper | Buy |
| 7 | Siege of Tarr-Hostigos | 2012 | Henry H. Beam Piper | Buy |
| 8 | The Hos-Blethan Affair | 2014 | Henry H. Beam Piper | Buy |
| 9 | Down Styphon! | 2016 | Henry H. Beam Piper | Buy |
Lord Kalvan of Otherwhen (1965) is set in the same universe as the Paratime Police stories but reads like a very different kind of book. Calvin Morrison, an ordinary Pennsylvania cop, gets scooped up by a Paratime conveyor and dumped on an alternate Earth where the technology level resembles late medieval Europe. He lands in Hostigos, a small kingdom being squeezed by Styphon’s House, a religious order that controls the secret of gunpowder production.
Morrison introduces his own knowledge of gunpowder chemistry and military strategy to even the odds. The Paratime Police discover what happened but decide to let him be, since he has built a cover story that protects the secret of cross-timeline travel. After Piper’s death, John F. Carr took up the series with several continuation novels, following Kalvan’s ongoing wars and political struggles across this alternate North America.