"Watch the Sky" by James H. Schmitz is a short novelet about an artifact, the war-souvenir Geest gun described below. This is a standalone story, not part of Schmitz's Agent of Vega or Federation of the Hub series, yet it has enough subtle background of its own sketched in to be memorable. It should not be overlooked.
Uncle William Boles' war-battered old Geest gun gave the impression that at some stage of its construction it had been pulled out of shape and then hardened in that form. What remained of it was all of one piece. The scarred and pitted twin barrels were stubby and thick, and the vacant oblong in the frame behind them might have contained standard energy magazines.
It was the stock which gave the alien weapon its curious appearance. Almost eighteen inches long, it curved abruptly to the right and was too thin, knobbed and indented to fit comfortably at any point in a human hand. Over half a century had passed since, with the webbed boneless fingers of its original owner closed about it, it last spat deadly radiation at human foemen. Now it hung among Uncle William's other collected oddities on the wall above the living room fireplace.
We don't learn much more about just what a Geest gun does than this opening description. The story is not a meditation on firearms, nor even on their psychological effects as in Robert Sheckley's "The Gun Without a Bang". Nor do we learn much about the Geest War or the aliens themselves; Schmitz says plenty but just enough in a sentence or two, here and there.
The Geest gun — the Gunderland Battle trophy on the wall — attracts plotters and generates a plot. Like Rudyard Kipling's bejeweled elephant-goad in "The King's Ankus", the Geest gun stirs ambition in people. More than in the Kipling though, these seem competent, thoughtfully dangerous men.
As usual with Schmitz, extra enjoyment comes from noticing tell-you-once key points and nuances. "Watch the Sky" repays slow reading, and rereading. A neat, tight story.