Racing for his coat and hat, he led the way to his car. A moment more and they were speeding back to the city. "Johnny," said the Captain, "do you believe that whisper came all the way from the city?" "I am sure of it." "A broadcast?" "No, not a broadcast. I feel sure no one in the world, save us, heard it." "Wonderful, if true--a revolutionary idea!" the Captain exclaimed. "I think," said Johnny, "that I could name the very spot from which that message came--the top of the Sky Ride tower." He told the Captain of his discovery regarding the whisper he had heard that morning. "We'll have to look into that," was the Captain's only comment. That very night Johnny attempted to "look into that," with such results as you shall see. CHAPTER XX THE SKY SLIDER Having secured Spider as his special bodyguard and obtained permission to enter the deserted grounds of the Century of Progress, Johnny set out on his mission of discovery. He was determined to learn what he could about the mysterious Whisperer. It was a dark night. Clouds hid the moon. One of those cold, gusty nights it was, when fine siftings of snow creep and tremble about your feet, when sharp gusts of wind shooting out from unexpected angles blow fine particles of ice upon your cheek, and you say with a start, "Some devil of the north has been let loose to blow his breath upon me." "Boo!" Spider shuddered. "How cold it is!" "Yes, and ghostly!" Johnny added. They were on the old Fair grounds. "When you think what this place has been, so full of light and sunshine, so hilarious with the screams and shouts of jolly revelers, every corner seems to hide a ghost." "Yes." Spider quickened his pace. "There's the place where they had all those freaks--tall, skinny men, short, crooked ones, two headed, one legged--all sorts of funny and distorted humans. Gee! Johnny, what a joy to have two legs and two arms, eyes, ears and all that!" "Yes, and what poor use some of us make of them!" Johnny grumbled. "Look." Spider was full of recollections. "There's where they kept that huge snake. Suppose he's in there now, all coiled up, torpid for his winter's sleep?" The thought caused him to veer sharply to the left. "Ghosts, all right," Johnny said quietly. "Ghosts of those who stood in these places hour by hour, patiently doing their duty, roasting hot dogs, guarding jewels, changing money, selling tickets. Ghosts too of performers on this hilarious Midway." "And ghosts of those who came to see," Spider chuckled genially. "But look!" Johnny's voice rose. He gripped Spider's arm. "Do I see a light up there, or don't I?" "Up where?" "Tower of the Sky Ride."