Comic Title: Challengers of the Unknown #3
Publisher: DC (National Comics Publications, Inc.)
Address: 480 Lexington Avenue, New York, NY
Cover Date: Aug/Sep 1958
On Sale Date: June 12, 1958 Copyright Date June 12, 1958
Source: Library of Congress, Periodicals 1958

Frequency: Bi-monthly
Cover Price: $0.10
Page Count: 32
Editor: Jack Schiff

Title: "The Menace of the Invincible Challenger"
Pages: 12

Feature(s):
Challengers of the Unknown (of Earth-1)

Writer/Artist: Jack Kirby

Reprinted In:
Challengers of the Unknown Archives Vol. 2 HC (2004)
Showcase Presents Challengers of the Unknown Vol. 1 TPB (2006)
Challengers of the Unknown Omnibus HC (2012)
Challengers of the Unknown by Jack Kirby TPB (2018)

Feature Character(s)

• Challengers of the Unknown (last appearance in Challengers of the Unknown #3; next appearance in Challengers of the Unknown #4)
• Ace Morgan (last appearance in Challengers of the Unknown #3; next appearance in Challengers of the Unknown #4)
• Rocky Davis (last appearance in Challengers of the Unknown #3; next appearance in Challengers of the Unknown #4)
• Red Ryan (last appearance in Challengers of the Unknown #3; next appearance in Challengers of the Unknown #4)
• Prof. Haley (last appearance in Challengers of the Unknown #3; next appearance in Challengers of the Unknown #4)

Supporting Character(s)

• June Robbins (last name given as Walker in this story; last appearance in Challengers of the Unknown #2; next appearance in Challengers of the Unknown #5)

Villain(s)

• Chopper, Roxie, and another unnamed fugitive (no further appearances)

Other Character(s)

• Professor Curtis (no further appearances)

Comments:
Rocky gains super powers temporarily in this story after a trip into space. The powers are similar to those that Kirby would later give the members of the Fantastic Four after a similar space flight.

Synopsis:
Rocky undergoes an experiment to test a new serum that might help may adapt to extreme environmental conditions. As part of the test, Rocky is launched into space and returns in a space capsule. He emerges from the capsule unharmed, but without his memory. He also now possesses strange powers including the ability to project fire or ice, grow or shrink to any size, and become invisible.

Without his memory, Rocky flees from his friends and is eventually found by three fugitives. The crooks plan to use Rocky for their own purposes, but the other Challengers find them. Rocky is wounded during the fight. He regains consciousness with his memory restored and finds his powers have disappeared.