"In a Flash of Realization, the Whole Puzzle Clicked into Place!"

"Mystery on Pluto."
By Ward Fleming (?-?).
First appearance: Fantastic Adventures, February 1950.
Short story (10 pages).
Online at UNZ HERE.
(Note: First page is inverted; use rotation button to correct.)
(Plus bonus vignettes — "Space School" and "Sky-Hooks" — HERE.)

"Frank Grove's mining business on Pluto was in danger of being ruined. And it was up to Nick Anders to find out the reason why . . ."

Sometimes all a successful thief has to do is inhale.

Principal characters:
~ Frank Grove, the superintendent of Interstellar Mining Company's plant on Pluto:
   ". . . somehow or other, small quantities of the element [faltronium] have been disappear-ing. This can only mean that it has been stolen. One of you men here—someone I trusted—is responsible!"
~ Ann Grove, "the old superintendent's pretty daughter":
   "Thought of Ann always made Nick [Anders] go soft inside. She was gay and charming, yet serious, and desperately loyal to anyone she loved. She was content to spend her days on desolate Pluto, gladly shouldering an innumerable assortment of minor tasks just to be with her father. Like faltronium, she was a rarity, the kind of girl that would make a splended wife."
~ Nick Anders, a lab technician working in I.M.C.'s Pluto facility:
   "Nick groaned. Hell, the whole setup was crazy from start to finish. Here he was, accused of something he hadn't done, and as good as bound for one of the more savage of the Jovian or Saturnian satellite penal colonies already. And Ann—Ann loved him. But she probably hated him now."
~ Guglo Atska, "the Martian who comprised the third member of the laboratory staff":
   "Atska was a furtive, queer old gnome who spoke only when absolutely necessary. If any-one was the thief, Nick felt that the little Martian would be the most likely."
~ Rod Boldt:
   "Almost fervently Nick wished that Boldt were the thief. Then, he thought wistfully, he'd have Ann all for himself. But Boldt couldn't be, for like Atska he came near faltronium only in gravel form."
~ Hans, the cook:
   "And Hans? Nick smiled in the darkness. The fat little Europian would give himself away immediately even if he had stolen so much as a speck of faltronium."

Pluto and its largest moon Charon compared to the Earth

Whiz-bang science:

   "Faltronium, as he knew, was used primarily as a catalyst to accelerate the reaction in the Gerelli-Stevenson rocket engines, which were the most economical and powerful yet devised. No other element was as effective. It had originally been discovered on Titan and after some experimentation, had been added to the list of known elements. Succeeding search had unearthed it on a few other out-lying planets and their moons. But the largest deposits yet discovered were on Pluto. These were owned by the famous Interstellar Mining Company.
   "Because of faltronium's scarcity it was easy to understand why stealing even the smallest quantity of it was a serious crime. Only radium of the last century had been as valuable and as rare."

Typo: "labortory"

Resources:
- The only information confirming that our author actually existed is on the ISFDb HERE; we suspect that he was the magazine's editor incognito.

- The planet Pluto has enjoyed the attention of science fiction writers ever since its discovery in 1930 (see Wikipedia HERE); thanks to the data still coming in from last year's New Hori-zons space probe flyby, the nonfictional Pluto is beginning to look a lot stranger than any-one, including "Ward Fleming," ever anticipated (see Wikipedia HERE).

The bottom line: Poor Pluto was demoted from full planethood in 2006, but in spite of that, to some of us Pluto was, is, and always will be a planet.