Daylight sometimes hides secrets that darkness will reveal-the Martian's glowing eyes, for instance. But darkness has other dangers.... Joseph Heidel looked slowly around the dinner table at the five men, hiding his examination by a thin screen of smoke from his cigar. He was a large man with thick blond-gray hair cut close to his head. In three more months he would be fifty-two, but his face and body had the vital look of a man fifteen years younger. He was the President of the Superior Council, and he had been in that post-the highest post on the occupied planet of Mars-four of the six years he had lived here. As his eyes flicked from one face to another his fingers unconsciously tapped the table, making a sound like a miniature drum roll. One. Two. Three. Four. Five. Five top officials, selected, tested, screened on Earth to form the nucleus of governmental rule on Mars. Heidel's bright narrow eyes flicked, his fingers drummed. Which one? Who was the imposter, the ringer? Who was the Martian? Sadler's dry voice cut through the silence: "This is not just an ordinary meeting then, Mr. President?" Heidel's cigar came up and was clamped between his teeth. He stared into Sadler's eyes. "No, Sadler, it isn't. This is a very special meeting." He grinned around the cigar. "This is where we take the clothes off the sheep and find the wolf."