Invisible

Patrick and Michael (Young Jack) Riordan go on a hiking trip in Europe with their girl friends. They stumble upon a lost cache of WW2 gold and set in motion a chase across Germany, where they uncover a blackmail attempt on the USA by a former Stasi General.

Pursued by a former SS sergeant and his gang of hitmen and crooks, they manage to escape capture more than once.

Finally, they upset the villian's plans to extort the US with a secret electronic device that renders conventional ships and aircraft invisible to all means of electronic surveillance.

Afast paced story of heros and villians.