I was playing Starcraft and used a Dark Templar to summon a Dropship, Battlecruiser and Carrier before moving to the top-right corner of the map. It was already too late when I realized I was walking into enemy territory and that my Dropship had disappeared. I redeployed a Command Center and Barracks before building a few Marines. I could see the distortion from invisible units walking all around the map on the Jungle tileset.