Launched from the Castle — Peter Reese Doyle

The seventh book in the exciting Daring Adventures series!

A pleasant excursion into a medieval castle turns dangerous when the teens discover evidence connected to a monstrous jewel heist from the home of a nearby German multi-millionaire. Taken by their German hosts to visit this wealthy businessman, Mark, Penny and David encounter the thieves, become separated, struggle to escape their captors, and must find a way to foil the thieving gang's helicopter get-away. How can they succeed?