Comic Title: Action Comics #303
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: August 1963
On Sale Date: June 27, 1963 Copyright Date June 27, 1963
Source: Library of Congress, Periodicals 1963

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

Title: "Supergirl's Big Brother"
Pages: 12

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

Writer: Leo Dorfman
Artist: Jim Mooney

Reprinted In:
Superman Family #175 (1976)
Showcase Presents Supergirl Vol. 2 TPB (2009)
Supergirl:The Silver Age Omnibus Vol. 1 HC (2016)
Supergirl:The Silver Age Vol. 2 TPB (2018)

Feature Character(s)

• Supergirl (last appearance in Action Comics #303; next appearance in Action Comics #304)

Supporting Character(s)

• Fred Danvers (last appearance in Action Comics #302; next appearance in Action Comics #304)
• Edna Danvers (last appearance in Action Comics #302; next appearance in Action Comics #304)
• Lori Lemaris (last appearance in Action Comics #302; next appearance in Superman's Girl Friend, Lois Lane #44)

Villain(s)

• Biff Rigger (a Jan Danvers imposter; no further appearances)
• Two jewel thieves (no further appearances)

Other Character(s)

• Jan Danvers (appears in flashback; son of Fred and Edna; revealed to be deceased; no further appearances)

Synopsis:
A man claiming to be Jan Danvers, the long lost son of Fred and Edna, arrives at the Danvers’ home. Supergirl reveals her identity to her new brother and makes a super power pill for him. After a tryout of his powers, the man’s cover is blown, and he tells Supergirl he is really Biff Rigger, a member of Jan’s old military unit. Biff threatens to reveal Supergirl’s identity if she stops him. When Supergirl’s life is threathened, Biff sacrifices his own for her, having learned compassion.