Transit to Scorpio by Alan Burt Akers

On the planet Kregen that circles Antares, the brightest star of the Constellation of the Scorpion, two forces contend for the world's destiny. One of them, the Savanti, called in a human pawn from far-away Earth.

His name is Dray Prescot, and only the Savanti know his role.

Dray Prescot confronts a fabulous world -- barbaric, unmapped, peopled with both human and non-human races. But the Star Lords always watch and check the Savanti's plans. And it soon turns out that Dray Prescot himself has to make a decision that will change him from a mere pawn to a bolder piece on the planetary chessboard...

Dray Prescot's saga has been aclaimed as the best planetary adventure series since Burroughs stopped writing about Barsoom.

Transit to Scorpio is the first book in the epic fifty-two book saga of Dray Prescot of Earth and of Kregen by Kenneth Bulmer writing as Alan Burt Akers. The next book in the series is The Suns of Scorpio.