Comic Title: G.I. Combat #121
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: Dec/Jan 1966
On Sale Date: October 11, 1966 Newsstand Date October 11, 1966
Source: Direct Currents, Adventures of Bob Hope #102

Newsstand Date October 11, 1966
Source: House Ad, Batman #187, Page 57

Copyright Date October 11, 1966
Source: Library of Congress, Periodicals 1966

Frequency: Bi-monthly
Cover Price: $0.12
Page Count: 32
Editor: Robert Kanigher

Title: "Battle of Two Wars"
Pages: 12

Feature(s):
Haunted Tank (of Earth-1)

Writer: Robert Kanigher
Artist: Russ Heath

Reprinted In:
Showcase Presents:Haunted Tank Vol. 2 TPB (2008)

Feature Character(s)

• Haunted Tank (last appearance in G.I. Combat #120; next appearance in G.I. Combat #122)
• Jeb Stuart (last appearance in G.I. Combat #120; next appearance in G.I. Combat #122)

Supporting Character(s)

• General J.E.B. Stuart (last appearance in G.I. Combat #120; next appearance in G.I. Combat #122)
• Rick Rawlins (last appearance in G.I. Combat #120; next appearance in G.I. Combat #122)
• Slim Stryker (last appearance in G.I. Combat #120; next appearance in G.I. Combat #122)
• Arch Asher (last appearance in G.I. Combat #120; next appearance in G.I. Combat #122)

Villain(s)

• Several German soldiers (no further appearances)

Other Character(s)

• Sgt. Mike Rock and a group of World War I infantry (no further appearances)

Comments:
This story shows Sgt. Rock's father, Mike, fighting in World War I. According to Who's Who #20, Rock's father's full name was John Michael Rock.

Synopsis:
Jeb Stuart and the Haunted Tank face off against an enemy tank positioned atop a hill. They shoot the ground under the tank causing it to fall from the cliff. To get out of the way of the falling tank, Jeb directs their tank into a cave, but the enemy tank seals off the entrance.

Jeb leads the Haunted Tank through the tunnels inside the cavern. The cave serves as a time portal transporting them back to World War I. They help a group of marines led by Sgt. Mike Rock fight off an enemy attack. Jeb realizes that Mike Rock is the father of the Sgt. Rock he knows.

Jeb then takes the tank back into the cave. They emerge in their own time through another exit, but immediately come under the fire of another German tank. This time Sgt. Mike Rock leads his infantry through the cave to help Jeb and his crew destroy the attacker. The World War I soldiers then return to their own time period via the time tunnel.