Story
Featuring
Superman
"For the first time in its history, the City of Metropolis is ravaged by a terrible earthquake!"
Storyline
When Clark Kent begins to investigate a new weapon being tested by the Army that artifically causes earthquakes, little does he know that Lex Luthor is hot on the trail of securing the plans for that invention, one way or the other.
Story Notes
The first story with Luthor was in Action Comics #23 (cover date April 1940). Superman asks "Who is Luthor?"
This is the second Luthor story. Luthor says "We encounter each other once more".
However this issue may have gone on sale before Action Comics #23. In their copyright registration, Detective Comics, Inc. said Action Comics #23 was published Feb 23, 1940. An in-house ad said Superman #4 would go on sale Feb 15; the copyright registration said that it was published Jan 23. Officially, per DC Comics web site, Luthor's first appearance is in Action Comics #23.
One panel promotional advertisement for the Spectre series in More Fun Comics (DC, 1936 series) at the end of the story, with art by Bernard Baily.