Comic Title: House of Secrets #53
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: Mar/Apr 1962
On Sale Date: January 23, 1962 Newsstand Date January 23, 1962
Source: House Ad, My Greatest Adventure #65, Page 8

Copyright Date January 23, 1962
Source: Library of Congress, Periodicals 1962

Frequency: Bi-monthly
Cover Price: $0.12
Page Count: 32
Circulation: 205000
Editor: Jack Schiff

Title: "Mark Merlin's Giant Double"
Pages: 9

Feature(s):
Mark Merlin (of Earth-1)

Penciller: Mort Meskin
Inker: George Roussos

Feature Character(s)

• Mark Merlin (last appearance in House of Secrets #52; next appearance in House of Secrets #54)

Supporting Character(s)

• Elsa Magusson (last appearance in House of Secrets #52; next appearance in House of Secrets #54)

Villain(s)

• Dr. Kaloz (alias Silas Ambrose; no further appearances)

Other Character(s)

• Za-Tor (a man from the futue; appears in flashback; no further appearances)
• A giant Mark Merlin robot (no further appearances)

Synopsis:
Mark Merlin receives a message from the future. The message is from Za-Tor, a time traveller that Mark has helped once before. Za-Tor tells Mark that he has sent him a gift. Before the gift arrives, Mark is approached by Silas Ambrose to investigate a giant that looks identical to Mark.

Mark and Ambrose locate the robot which was buried after its last appearance hundreds of years earlier. The robot sees Mark and tries to attack him. Mark escapes and discovers that Ambrose is his old foe, Dr. Kaloz. Mark manages to reprogram the robot, which then captures Kaloz. The robot's originally intent was to aid Mark, having been sent through time by Za-Tor. Unfortunately, the robot was sent too far into the past and existed centuries before Mark found it.