Comic Title: Superman's Pal, Jimmy Olsen #75
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: March 1964
On Sale Date: January 16, 1964 Copyright Date January 16, 1964
Source: Library of Congress, Periodicals 1964

Newsstand Date January 16, 1964
Source: Newsdealer Magazine, V19 #1

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

Title: "The Mystery of Convict 313"
Pages: 9

Feature(s):
Jimmy Olsen (of Earth-1)

Writer: Leo Dorfman
Artist: John Forte

Feature Character(s)

• Jimmy Olsen (last appearance in Superman's Girl Friend, Lois Lane #47; next appearance in Superman's Pal, Jimmy Olsen #75)

Supporting Character(s)

• Superman (last appearance in Superman's Girl Friend, Lois Lane #47; next appearance in Superman's Pal, Jimmy Olsen #75)
• Perry White (last appearance in Superman's Girl Friend, Lois Lane #47; next appearance in Superman's Pal, Jimmy Olsen #75)
• Lois Lane (last appearance in Superman's Girl Friend, Lois Lane #47; next appearance in Superman's Girl Friend, Lois Lane #48)

Villain(s)

• The Brain (impersonates Mark Olsen; dies in this story; no further appearances)
• An unnamed assassin (no further appearances)
• Inmates at Metropolis Prison (no further appearances)

Other Character(s)

• Rick Mason (a reporter for the Sentinel; no further appearances)
• The warden and guards at Metropolis Prison (no further appearances)
• Mark Olsen (behind-the-scenes in flashback; last appearance in Adventure Comics #216; next appearance in Superman's Pal Jimmy Olsen #124)
• Mrs. Olsen (dies behind-the-scenes in flashback; last appearance in Adventure Comics #216; no further appearances)

Flashback Appearance(s)

• Jimmy Olsen (as a young boy; last appearance in Adventure Comics #216; next appearance in Superman's Pal, Jimmy Olsen #36)

Cameo Appearance(s)

• Lucy Lane (in a photo)

Synopsis:
Jimmy Olsen receives an anonymous message about Convict 313 in Metropolis Prison. Jimmy investigates the prisoner and finds out that it is his missing father Mark Olsen. Jimmy is embarrassed that his father is a criminal, but he saves his father's life in prison twice.

Mark Olsen offers to turn over loot he stole to Jimmy and Superman. When Superman opens the chest with the loot, he finds Kryptonite inside. Then an assassin tries to kill both Jimmy and Superman. Mark Olsen has escaped jail and stops the assassin. He then reveals that he is not Jimmy's father. He was working with the Anti-Superman Gang. When Jimmy saved his life, he felt bad and turned against them. In stopping the assassin, he is wounded and dies.