Because of the Auxiliary Brain's precise control, the destruction caused by the Drone to the ships was very skillful. This destruction was just enough to force the ships to stop, yet not enough for anyone to discover what was damaging them. If the ships continued to move forward, the Drone would throw large stones from Universal Space, which would strike the underside of the ship in a certain arc, making the ship think it had hit a reef and had no choice but to turn back, which is why those ships were puzzled about their sudden reef collisions. But as soon as these ships turned back, the Drone would cease its attacks and let them leave the area.
In this way, the Drone inconspicuously blocked these ships from advancing toward Misty Island and caused them to retreat out of suspicion and fear.
