MINDSWAP

Ace paperback, 1978. Cover painting by Howard Darden.

"It all started with a perfectly ordinary classified ad: 

"Gentleman from Mars, age 43, quiet, studious, cultured. Wishes to exchange bodies with similarly inclined Earth gentleman; August 1 - September 1. References exchanged, Brokers Protected."

At 31, Marvin Flynn was practically an adult; was it merely the vestiges of adolescent foolishness that sent him to the body-brokerage firm of Otis, Blanders and Klent? Or was it extraterrestrial fervor? Whatever it was,  Marvin knew he must see the Burrows of Mars, the Talking Ocean, the Disappearing Desert and - above all - Mud Heaven. 

What he didn't know was that more than one person had claims on the body of Ze Kraggash, and that before he was finished he would see more strange sights - through even stranger eyes - than he had ever imagined. That in his desperate struggle for continued corporeal existence he would fall pray to Metaphoric Deformation, the limitations of the Set-Expansion Factor, and at last descend/ascend/extend to the strange and unexplainable reaches of the Twisted World - for the ultimate MINDSWAP"