A pulp potboiler from Project Gutenberg.
Poisoned Air by S. P. Meek
"Again Dr. Bird closes with the evil Saranoff—this time near the Aberdeen Proving Ground, in a deadly, mysterious blanket of fog."
This story is part of Meek's series about scientific Sherlock Holmes knock-off, Dr. Bird. Whereas Holmes contended against the criminal mastermind, Moriarty, Bird's nemesis is the evil Russian Saranoff, who in true Red Scare fashion has it in for the U.S.A. Meek, who died on this day in 1972, is notorious for being one of the worst writers of the early pulps.