The Infinity Clue

A hasty warning message from their father, sent through the German Ambassador, summons the Hardy boys to Washington, D.C., on a case that spells trouble with a capital T. An antinuclear "demonstrator" smashes their car window, and an exploding Frisbee nearly ends their career! The only clue is the Frisbee with a figure 8 on its side: the infinity symbol.

What does the symbol mean? Does it have anything to do with the mysterious earthquake that shook Bayridge Nuclear Power Plant? Frank and Joe set out on a dangerous chase for the answers. From the eerie cellars of the Smithsonian Museum through Washington's back alleys to remote offshore islands, the brothers race against time to find a priceless stolen diamond, a gang of high-tech hoodlums, and their father, whose life hangs in the balance!