With a subdued hissing sound, a luminous sphere emerged from the fireplace, moving slowly, parallel to the wall and knee-height from the floor. The sphere was half the size of a football, and moved horizontally, set away from the wall by an arms-length. Both Toshiro and his uncle gazed at this apparition in profound fascination. Then the sphere suddenly vanished, leaving a faint smell of ozone and nitric oxide as the only vestiges of its passing. The whole experience had probably lasted less than two seconds. They remained silent and heard a distant roll of thunder.

There had been no sharp...