The narrator, along with his pals Dettner and Lasker, are frantically working on a machine that can bring something back from the future before they’re all called away by the army to work on some cockroach problem.

I enjoy stories with some personal connection to myself (and generally award an extra half star). In this case, the connection is Alfred Tarski, the Polish logician who was the advisor of the advisor of my own academic advisor, David B. Benson.