In his first story appearance, Action Comics #23 (April 1940), Luthor is depicted as a diabolical genius and is referred to only by his surname. He resides in a flying city suspended by a dirigible and plots to provoke a war between two European nations. Lois Lane and Clark Kent investigate, which results in Lois being kidnapped. Luthor battles Superman with a green ray but he is ultimately defeated, and Lois is rescued. Superman destroys Luthor's dirigible with him still on it, implying Luthor may have died. Stories ending with Luthor's apparent death become common in his earliest appearances, with him turning up alive later on.