"The Red Queen's Race" was first published in the January 1949 issue of Astounding Science Fiction and reprinted in the 1972 collection The Early Asimov.
"The Red Queen's Race" was written in July 1948, a month after Asimov received a PhD from Columbia University and became a postdoc studying anti-malarial drugs.
His plan was to "improve" the world by giving Hellenic Greece advanced knowledge in the form of chemistry.
The investigating agents and their superior, The Boss, gradually realize that the changes introduced into history might, through the butterfly effect, cause the deletion from existence of every human being alive.
The trail eventually leads to the doorstep of Mycroft James Boulder, Assistant Professor of Philosophy, who had been hired by Tywood to translate a textbook of chemistry into Attic Greek.