Following a wildfire, a family discovered a smooth metallic sphere approximately 20 centimeters in diameter. No seam. No marking. No identifiable alloy. When placed on a hard surface it rolled in one direction, stopped, reversed, and returned — against the gradient of the floor. It hummed at irregular intervals.

When a family member played guitar in its presence the humming intensified and changed pitch in apparent response. The US Marine Corps requested the object for examination. It was returned without comment. Then requested again. It was not returned the second time. The family never saw it again.

No record exists of what analysis was conducted. The sphere's current location is 封存.

The humming frequency, when analyzed by independent researchers who had access to recordings made before the sphere's confiscation, was measured at 7.83 Hz.