Three soldiers, one English, one French and one German, are captured by the Taliban in Afghanistan. Their captors take them to a mine field and tell them that if they can escape to the checkpoint on the other side, they are free to go. To do so they offer them each whatever transport they want to cross it. The Englishman chooses a Rover, solidly built enough to take a blow from a mine perhaps. He hits a mine and explodes. Dead. The Frenchman chooses a Renault, small and quick so it may be able to get between the mines, he thinks. He hits a mine and explodes. Dead. The German asks for a large rubber duck, with a spring stuck on each corner. The Taliban suspect him to be mad, but its good sport so they find him a big rubber duck and kit it out as per his instructions. He bounces his contraption over the mine field. He hits a mine and explodes. But the explosion carries him forward and he bounces to the next one. He crosses the whole minefield unharmed. The Taliban at the other side are perplexed by this. ""How did you ever manage to devise such a solution to crossing minefields?"" they ask. ""Oh it is an old German method,"" he replies, ""We call it the Four-Sprung Duck Technique.""