The first volume of what will be a multi-book saga: Tom Swift faces two parts of an old comet that have started heading toward Earth. The news media attempts to stir up a really big panic about it all, yet not very many astronomers are certain that it isn't just a tempest in a teacup. Until the day it turns out to be much more than that. While governments dither and scientists endlessly debate, and while religious zealots want people to just give up and pacifists fight with those who say that a nuclear deterrent is what's called for, Tom and his team at Swift Enterprises leap into action....