What happened in chapter 7 of the boys who challenged Hitler?

In Chapter 7 of The Boys Who Challenged Hitler, the boys of the Danish resistance movement, known as the Churchill Club, are preparing to launch their first major operation. The plan is to sabotage a German ammunition train that is passing through the Danish countryside. The boys are able to successfully derail the train, but the Germans quickly respond by sending in reinforcements. The boys are forced to flee, but they are able to escape without any casualties.