Barrage balloons were first used in WWI ... "Attackers attempting to shoot down a balloon could be caught in an explosion of the hydrogen used to get them airborne," the report adds.

Click on it, and a barrage of balloons will float up – just like the balloons Mark S received from Milchick when he returned ...

The platoon discover a runaway barrage balloon and decide to release it safely themselves. This proves not to be wise, when the balloon flies away with Captain Mainwaring still hanging onto it.