At a school-benefit sale, Pete Hollister buys an old book about early New York tunnels. Tucked in the pages is a message written in Chinese. The only English word in it is �??Help!�?� The Hollisters take the mysterious note to a Chinese friend for translation and learn that the letter was written many years earlier in China by a Yuen Foo to his son in New York, but was never mailed. Pete, who has been trying out a new detective kit, tests the letter for possible invisible ink, and is rewarded when concealed Chinese writing shows up. It says Yuen Foo was being threatened because of the �??treasure.�?� Mr. Hollister has been invited to New York as consultant to a toy manufacturer who is trying to perfect a toy called the �??Soaring Satellite.�?� Mr. Hollister decides to take the family with him for a vacation. The children are pleased not only because of the things to see in New York, but because the clues point to New York�??s Chinatown as the location of and answer to the mystery surrounding the letter. his book is a tour of one of the most famous cities in the world as well as an introduction to a little piece of China and the Chinese way of life a