Comic Title: Action Comics #317
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: October 1964
On Sale Date: August 27, 1964 Copyright Date August 27, 1964
Source: Library of Congress, Periodicals 1964

Frequency: Monthly
Cover Price: $0.12
Page Count: 32
Editor: Mort Weisinger

Notes:
This issue contains a half-page text feature: "The Story of Lena Thorul".

Title: "The Great Supergirl Double-Cross"
Pages: 12

Feature(s):
Supergirl (of Earth-1)

Writer: Leo Dorfman
Artist: Jim Mooney

Reprinted In:
Superman Family #166 (1974)
Showcase Presents Supergirl Vol. 2 TPB (2009)
Supergirl:The Silver Age Omnibus Vol. 2 HC (2018)

Feature Character(s)

• Supergirl (last appearance in Action Comics #316; next appearance in Adventure Comics #325)

Supporting Character(s)

• Fred Danvers (last appearance in Action Comics #316; next appearance in Action Comics #318)
• Edna Danvers (last appearance in Action Comics #316; next appearance in Action Comics #318)
• Lena Thorul (last appearance in Action Comics #316; next appearance in Adventure Comics #387)
• Dick Malverne (last appearance in Action Comics #316; next appearance in Action Comics #318)

Villain(s)

• Lex Luthor (last appearance in Superman #172; next appearance in Action Comics #332)
• Members of an international spy ring (no further appearances)

Other Character(s)

• Jeff Colby (Lena's boyfriend; marries Lena in this story; no further appearances)
• A robot duplicate of Colby (no further appearances)

Synopsis:
Supergirl discovers that Lena Thorul's new boyfriend Jeff Colby is part of an international spy ring. When Colby proposes, Supergirl decices to break them up to save Lena the shame of marrying a spy. As Linda, Supergirl hypnotizes Jeff and makes him appear fickle. Her plan works as Lena breaks off their engagement.

Supergirl then reports Jeff to the FBI where she learns that he is a double-agent. He has infiltrated the spy ring in an attempt to arrest them. Embarrassed by her mistake, Supergirl helps Jeff defeat the spies. She then patches things up between Jeff and Lena, who then get married.