The Flies, who bear an amazing resemblance to household insects grown to five-foot length, come to Earth with a stated goal of “remembering” it. Earth’s ambassadors arrange for the Flies to visit various cities, hoping that cooperation will persuade the Flies to reveal their secret of long-distance space travel. In an attack by an angry crowd, however, a Fly dies in an explosion of its power pack, and at the same instant, the cupola of St. Peter’s vanishes.
The Flies insist that the disappearance is an accident, but Earth’s authorities respond aggressively, storming the aliens’ ship. The occupiers prevent Flies from reentering their ship until several more Flies die and parts of various cities disappear. Earth scientists quickly figure out that the Flies’ “memories” of places are tied to the existence of those places, and unless the Flies disgorge their memories into their ship, the places disappear.
Part of Munich that had been lost in a Fly’s memory reappears on Mars. Three ships from Earth travel to Mars, their crews intent on discovering the secret of how Munich was transported. The political problems of this international expedition fill the bulk of the book. Although Watson does an excellent job of portraying ideological battles on the small scale of the expedition, he makes THE FLIES OF MEMORY more than a political study by keeping the plot linked to the Flies’ peculiar form of memory. Watson’s story easily could have become a heavy-handed political treatise. Instead, he leaves the reader with questions about the future of humanity rather than his own dogmatic predictions of that future. His device of switching point of view from character to character enhances the sense of universal experience.