During the second event of The Black Knight Challenge following the exhausting eight-mile ruck march was a timed five-gallon water jug relay at Bagram Air Field, Afghanistan Sept. 17. Each member of the team carried two water jugs 100 meters down a road to an awaiting teammate who then lugged the jugs back the start point. (Photo by Staff Sgt. Michael K. Selvage, 10th Sustainment Brigade Public Affairs NCO)(Released)