Barry Williams watched the last sunshine lance across the red sands of the Martian Desert. The sun dropped abruptly behind the flat horizon. With the black curtain of night, the usual sharp chill came to the thin Martian atmosphere. The cold bit into Williams through the warm ore-seeker's outfit he'd adopted for this venture. He laughed suddenly, realizing why he noticed the cold. His body was tense, rigid. Unconsciously he was crouching, waiting, eyes narrowed, one heavily-gloved hand on his ra