Riddle Number Ten Henry, manager of the Dead Sea Resort, was lounging in his room when he got a phone call from an angry customer. "My little son was swimming in your Dead Sea and drowned! I was watching him, but when I looked away for a second, he was gone! He had managed to get into the sea while my back was turned. I tried to get to him, but I was too late. He sunk right under and drowned! Unless you can pay us in return for taking our son's life, I'll sue you! There was no lifeguard, and my son and I were the only people there. Come down here right now, while I'm still alone, and pay me some money!" Henry immediately hung up and called the police. How did he know that the "angry customer" was lying?