"And if you can't measure time, then there is no time: so you see you can't waste time or spend time when you're on the North Pole. I hope you understand that." "Yes sir," answered Billy dubiously. "Then come along and cut your initials in the pole." "Please do," pleaded Sterry. And Billy was just about to yield--indeed, he had taken two steps toward the door when King Calcium suddenly exclaimed: "Hold! Jack, lock the doors; Billy Bounce, you are discovered." "What! Billy Bounce in our mongst?" cried Jack, blowing on the doors and freezing them tight shut. "Not the real Billy," cried Sterry, walking over to a sofa and preparing to faint. "Yes," cried the King, "it is indeed he--Nickel Plate has just wigwagged me that he is in this room." "I am undone!" screamed Sterry, throwing herself carefully onto the sofa. "Seize him, Jack!" cried the King. "Seize him yourself," said Jack, dancing away out of Billy's reach; "remember I'm a nervous child." "I will," cried the King, tottering over to Billy and laying his hand on his collar. "Jack, call the ice guard." "Ice guard, ahoy!" shouted Jack. "Lemme go," cried Billy, "or I'll----" "No you won't," panted the King, clinging desperately to Billy. "You'll see," said Billy, and began to drag the King over to the window where the calcium was burning brightly. "Help me, help me, Jack!" called the King, trying to sit down on the floor. But Billy kept him from doing so, and finally reached the window. Quick as a flash he turned the entire Northern Light right into the room, and with a sizzle, splash--puff the ice doors went up in steam. The next moment he found the lever that controlled the lamp, and zip the light was out. My, my, my but how dark it got--darker than a thousand nights--blacker than a million hats. The King let go of Billy's collar and commenced wildly to grope for the machine. "Now to escape," cried Billy. "Barker, lead me out by scent," and quickly he pulled Barker out of his pocket, tied a string to his collar and turned him loose. Barker gave one little yelp, and then darted for the doorway with Billy hot after him. Out they ran into the open air, and picking Barker up in his arms, up jumped Billy away from Aurora Borealis. CHAPTER XV. BILLY MEETS GLUCOSE. To say that Billy was glad to see real sunshine and feel its warmth again, hardly expresses his joy, when, on emerging from Aurora Borealis, he floated into a warmer climate. And the next time his feet touched earth it did not take him long to take off his rabbit skin and give it back to the Singing Tree. And then how he and Barker rolled on the soft green grass, breathed in the sweet, flower-scented air, and basked in the sunlight! "You saved my life, old boy," said Billy, patting Barker's head. And Barker wagged his little tail and cocked his head on one side, as much as to say: "I'm glad, and I would do it again if I had the opportunity, Billy Bounce."