Search (Left Behind: The Kids #9) by Jerry B. Jenkins, Tim LaHaye

As World War III erupts, the Young Trib Force loses one of the most important people to them in the world. Also, Judd, Vicki, Lionel, and their friends set out on a desperate search to find Ryan.

The Young Tribulation Force attempts a rescue before another air attack by the Global Community. In the process, the kids face new dangers and encounter a top Global Community official.