Comic Title: Adventure Comics #378
Publisher: DC (National Periodical Publications, Inc.)
Address: 909 Third Avenue, New York, NY
Cover Date: March 1969
On Sale Date: January 30, 1969 Copyright Date January 30, 1969
Source: Library of Congress, Periodicals 1969

Newsstand Date January 30, 1969
Source: Comic Reader, #71

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

Title: "Twelve Hours to Live"
Pages: 23

Feature(s):
Legion of Super-Heroes (of Earth-1)

Writer: James Shooter
Penciller: J. Winslow Mortimer
Inker: Jack Abel

Reprinted In:
Legion of Super-Heroes Archives Vol. 9 HC (2000)
Showcase Presents:Legion of Super-Heroes Vol. 4 TPB (2010)
Legion of Super-Heroes:The Silver Age Omnibus Vol. 3 HC (2020)

Feature Character(s)

• Legion of Super-Heroes (last appearance in Adventure Comics #377; next appearance in Adventure Comics #379)
• Duo Damsel (last appearance in Adventure Comics #377; next appearance in Adventure Comics #379)
• Brainiac 5 (last appearance in Adventure Comics #377; next appearance in Adventure Comics #379)
• Superboy (last appearance in Superboy #154; next appearance in Adventure Comics #379)
• Karate Kid (last appearance in Adventure Comics #377; next appearance in Adventure Comics #379)
• Princess Projectra (last appearance in Adventure Comics #377; next appearance in Adventure Comics #379)

Villain(s)

• Fatal Five (last appearance in Adventure Comics #366; next appearance in Superboy #198)
• Mano (last appearance in Adventure Comics #366; next appearance in Superboy #198)
• Tharok (last appearance in Adventure Comics #366; next appearance in Superboy #190)
• Emerald Empress (last appearance in Adventure Comics #366; next appearance in Superboy #198)
• Validus (last appearance in Adventure Comics #366; next appearance in Superboy #190)
• Persuader (last appearance in Adventure Comics #366; next appearance in Superboy #198)
• Alek Korlo (not named in this story; next appearance in Adventure Comics #379)

Guest Appearance(s)

• Jonathan Kent (last appearance in Superboy #154; next appearance in Superboy #157)
• Martha Kent (last appearance in Superboy #154; next appearance in Superboy #157)
• Lana Lang (last appearance in Superboy #154; next appearance in Superboy #155)

Other Character(s)

• Myron Marks (a park bench philosopher; no further appearances)
• Mr. and Mrs. Durgo (last appearance in Adventure Comics #359; no further appearances)

Comments:
Part 2:"In the Shadow of Death"

This story continues in Adventure Comics #379.

Synopsis:
At a celebration of Brainiac 5's birthday, five Legionnaires are poisoned. Brainiac 5 analyzes the poison and determines that it will kill each of them in twelve hours. Brainiac 5 uses the time to find a cure. Superboy returns to the 20th century and attempts to stay busy. Duo Damsel returns home to visit her parents for the last time. Karate Kid tracks down the Fatal Five on a suicide mission. Projectra mopes around the city until she meets Myron Marks, who lifts her spirits.

As the twelve hour period comes to an end, the poisoned Legionnaires return to headquarters. Brainiac 5 admits that he could not find an antidote. The Legionnaires then compose a will, before each succumbs to the effects of the poison. Brainiac 5 makes one last effort to save them using the Miracle Machine, but he runs out of time. When all the Legionnaires fall unconscious, their killer gloats over his victory.