Comic Title: Challengers of the Unknown #68
Publisher: DC (National Periodical Publications, Inc.)
Address: 909 Third Avenue, New York, NY
Cover Date: Jun/Jul 1969
On Sale Date: April 1, 1969 Copyright Date April 1, 1969
Source: Library of Congress, Periodicals 1969

Newsstand Date April 1, 1969
Source: Comic Reader, #72

Frequency: Bi-monthly
Cover Price: $0.12
Page Count: 32
Editor: Murray Boltinoff

Title: "One of Us Is a Madman"
Pages: 24

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

Writer: Dennis J. O'Neil
Penciller: Jack Sparling
Inker: Vince Colletta

Feature Character(s)

• Challengers of the Unknown (last appearance in Challengers of the Unknown #67; next appearance in Challengers of the Unknown #69)
• Ace Morgan (last appearance in Challengers of the Unknown #67; next appearance in Challengers of the Unknown #69)
• Red Ryan (last appearance in Challengers of the Unknown #67; next appearance in Challengers of the Unknown #69)
• Rocky Davis (last appearance in Challengers of the Unknown #67; next appearance in Challengers of the Unknown #69)
• Prof. Haley (last appearance in Challengers of the Unknown #67; next appearance in Challengers of the Unknown #69)

Villain(s)

• Robert Fillmore (no further appearances)
• A computer creatrue (no further appearances)

Other Character(s)

• The President of the United States (no further appearances)

Synopsis:
The Challengers are enlisted by the President to investigate strange events surrounding a nuclear detection facility in New Mexico. Several key figures at the facility have gone insane and their dementia is being attributed to supernatural phenomenon.

When the Challs enter the facility they are attacked by a computer creature made of electrical wire. Their guide Dr. Fillmore has also been corrupted and tries to kill them. Rocky is critically injured while saving Ace. Prof then falls victim to the computer's mental control. He tries to kill his own teammates, but Fillmore interrupts. Ace destroys the computer, and the Challs exit the facility safely. However, Prof's mind remains compromised by evil.