Jerry Morgan, a man with no future on Earth, is offered a new life on Mars. He starts out on the wrong foot, meeting a princess and killing the fearsome-looking Martian beast he takes to be menacing her, which actually turns out to be her pet. From there Morgan becomes entangled in the politics of the Byzantine Martian royal court, spurns the advances of a would-be lover, escapes his hosts and role as an expendable political pawn. Various adventures follow, with dazzling swordplay, feats of strength, and other trials, tribulations and treacheries.
Kline's Mars has multiple parallel canals, surrounded by walls and terraces, and the construction of the canals by Martian machines is described. The story has a race-war element that may jar the modern reader.