Comic Title: Superboy #104
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: April 1963
On Sale Date: February 14, 1963 Newsstand Date February 14, 1963
Source: House Ad, Action Comics #298, Page 16

Copyright Date February 14, 1963
Source: Library of Congress, Periodicals 1963

Frequency: Monthly, with the exception of Feb., May, Aug., and Nov.
Cover Price: $0.12
Page Count: 32
Editor: Mort Weisinger

Title: "The Untold Story of the Phantom Zone"
Pages: 26

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

Writer: Edmond Hamilton
Artist: George Papp
Penciller: Curt Swan
Inker: George Klein

Reprinted In:
Superman:Tales from the Phantom Zone TPB (2009)

Feature Character(s)

• Superboy (last appearance in Adventure Comics #306; next appearance in Adventure Comics #307)

Supporting Character(s)

• Jonathan Kent (last appearance in Adventure Comics #306; next appearance in Adventure Comics #307)
• Lana Lang (last appearance in Adventure Comics #306; next appearance in Adventure Comics #307)
• Jor-El (in flashback; last appearance in Superboy #87; next appearance in Superman #77)
• Lara (in flashback; last appearance in Superboy #87; next appearance in Superman #77)
• Police Chief Parker (last appearance in Adventure Comics #306; next appearance in Adventure Comics #307)
• Krypto (in flashback; last appearance in Superboy #87; next appearance in Adventure Comics #287)

Villain(s)

• Gra-Mo (a Kryptonian scientist; also appears in flashback to Krypton’s past; next appearance in Superboy #162)
• Gra-Mo's henchmen (no further appearances)
• Ha-Kor (a Kryptonian criminal; no further appearances)
• Jax-Ur (last appearance in Superboy #102; next appearance in Adventure Comics #313)
• Professor Vakox (in flashback; last appearance in Action Comics #336; next appearance in Superman's Pal, Jimmy Olsen #101)
• Dr. Xadu (in flashback; last appearance in Adventure Comics #283; next appearance in Superboy #100)
• Various unnamed Phantom Zone prisoners (no further appearances)
• Reginald (an android boy created by Gra-Mo; destroyed in this story; no further appearances)

Other Character(s)

• Various Kryptonian citizens (no further appearances)

Flashback Appearance(s)

• Kal-El (as a baby on Krypton; last appearance in Superboy #87; next appearance in Superman #77)
• Jax-Ur (last appearance in Action Comics #336; next appearance in Superman's Pal, Jimmy Olsen #101)

Cameo Appearance(s)

• Martha Kent (in flashback to Kal-El's arrival on Earth)

Comments:
Chap 1. : "The Crimes of Krypton’s Master Villains"
Chap 2. : "The Kid Who Knocked Out Superboy"

Synopsis:
Years ago on Krypton, Jor-El invented a device to send criminals into the Phantom Zone. The projector device was demonstrated to the leaders of Krypton during a scientific contest. Jor-El was awarded a seat on the science council for his invention, while his competitor, Gra-Mo is angered.

Gra-Mo takes his revenge by causing the robot police of Krypton to attack. Jor-El stops the revolt with the magnetism generated by a weather satellite. Gra-Mo is convicted and exiled into space with his henchmen because the Phantom Zone projector has been disabled temporarily. Years later, Gra-Mo lands on Earth.

Gra-Mo meets Superboy and decides to enact revenge against Jor-El’s son. He tricks Superboy into believing that the Boy of Steel is responsible for a boy’s death. Superboy quickly sees through the trick and pulls one of his own in order to banish Gra-Mo and his men to the Phantom Zone.