"It's the Fountain of Youth!!! After all our searching, we've found it!" Suddenly Moby heard a growl. He and Tim spun around. There in front of them was a Griffin. "Greetings" growled the griffin. His voice was deep. "I see you have found the Fountain of Youth. But do not tell about it" he said warningly. But if you do not tell anyone of it, then good fortune will befall you. " But how can we bathe in it?" asked Tim. You must answer this riddle to do so" said the griffin. " I cannot be seen, heard, smelled, tasted and felt. What am I?"