Tom Swift and His Great Searchlight is the 17th book in the Tom Swift series by Victor Appleton. In this book, Tom uses his latest invention, a powerful searchlight, to help Uncle Sam find enemy submarines near the US border. The searchlight attracts the attention of foreign spies, and Tom and his friends find themselves in dangerous situations as they work to protect the country. The book features exciting adventures, thrilling chases, and clever inventions, making it a perfect read for young adults who love action and technology.