Comic Title: Action Comics #321
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: February 1965
On Sale Date: December 31, 1964 Newsstand Date December 31, 1964
Source: House Ad, Superman #175, Page 20

Copyright Date December 31, 1964
Source: Library of Congress, Periodicals 1965


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

Title: "The Enemy Supergirl"
Pages: 10

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

Writer: Leo Dorfman
Artist: Jim Mooney

Reprinted In:
Showcase Presents Supergirl Vol. 2 TPB (2009)
Supergirl:The Silver Age Omnibus Vol. 2 HC (2018)

Feature Character(s)

• Supergirl (last appearance in Superman's Girl Friend, Lois Lane #55; next appearance in Action Comics #322)

Supporting Character(s)

• Fred Danvers (last appearance in Action Comics #319; next appearance in Action Comics #324)
• Edna Danvers (last appearance in Action Comics #319; next appearance in Action Comics #324)
• Comet (last appearance in Action Comics #318; next appearance in Action Comics #323)
• Miss Hart (last appearance in Action Comics #299; next appearance in Action Comics #340)

Villain(s)

• Jax-Ur (last appearance in World's Finest Comics #146; next appearance in Superman #179)
• General Zod (last appearance in Action Comics #309; next appearance in Adventure Comics #395)
• Various unnamed Phantom Zone prisoners (no further appearances)
• Debbie Porter (disguised as Supergirl in this story; no further appearances)
• Various unnamed criminals (no further appearances)

Other Character(s)

• Children from Midvale Orphanage (no further appearances)
• Diane (a student; no further appearances)

Synopsis:
Supergirl uses a piece of Red Kryptonite to temporary remove her invulnerability, allowing her to donate blood. A hospital patient, Debbie Porter, receives the blood while recovering from a head injury. Debbie gains super powers and impersonates Supergirl. The phony Supergirl turns to crime and learns her counterpart's secret identity.

After several encounters, the real Supergirl finally deduces Debbie is the imposter. She uses Kryptonite to force a confession from Debbie. Fortunately, the super powers were temporary. When they wear off, Debbie returns to normal, believing her experiences as Supergirl were merely a dream.