In novel 30 of the series, Tom Swift seems to be facing something he could scarcely believe possible a couple years earlier. When a mystery object crashes into a walkway at Swift Enterprises-just feet behind the inventor-it is the start of either one of Tom an Damon Swift's most recent joys... of the start of a terrible nightmare!The Space Friends had disappeared from the solar system a couple years earlier, but it seems they are coming back. And, they will not (or cannot) tell Tom why they are coming. Once they do, a huge surprise is in store for everyone. Even the President of the United States has no idea what to do and allows the Swifts to "run the show."Tom must plan to do something neither Swift has ever considered to be an option; he must design and construct an offensive weapon just in case the visit turns out to not be a friendly one.