Tomorrow People, The (Rare Vintage Paperback) by Judith Merril

Something on Mars was killing people!

An ill-fated expedition to the Red Planet vanished without so much as a trace. On another expedition, only one man came back alive. That man was Johnny Wendt, and he was the only man to ever set foot on Mars and return to tell about it. His knowledge could prove to be decisive in the desperate East-West race for outer space superiority. Unfortunately, Johnny Wendt didn’t know just exactly what it was that made Mars a death trap…and he didn’t know that he’d brought it back with him!