2 intensely bright white lights in the north sky suddenly disappear.2 of the brightest lights I have ever seen were in the Northern Sky. We, meaning my family, were camping in the middle of the prairie about 30 miles north of Mandan, far away from city or artificial lights. The others had gone inside the camper and my brother and I were sitting around a campfire, enjoying a beautiful, clear night of looking at the stars when suddenly 2 extremely bright lights appeared high in the north. They were intensely bright and seemed to hover for the longest time with no sound. It was amazing how bright they were. Then one of them seemed "to power down" and get dim to the point of disappearing and the other flew off. I said to my brother, "did you see that?" He said he did. I asked him what he thought it was and he said it was nothing he'd seen before or could understand.