Comic Title: House of Secrets #57
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: Nov/Dec 1962
On Sale Date: September 20, 1962 Copyright Date September 20, 1962
Source: Library of Congress, Periodicals 1962

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

Title: "The Invader from the Shadow World"
Pages: 9

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

Writer: Jack Miller
Artist: Mort Meskin

Feature Character(s)

• Mark Merlin (last appearance in House of Secrets #56; next appearance in House of Secrets #58)

Supporting Character(s)

• Elsa Magusson (last appearance in House of Secrets #56; next appearance in House of Secrets #58)

Villain(s)

• A shadow creature (destroyed in this story; no further appearances)

Other Character(s)

• Dr. Frank Gunther (no further appearances)

Synopsis:
Mark Merlin is invited to see the black light experiments of Dr. Frank Gunther. While creating a crystal to use in the device, Gunther accidentally releases a creature made from Mark Merlin's shadow. The shadow creature possesses destructive power and seeks out a natural deposit of crystal in order to release more creatures. Mark uses Gunther's black light to destroy the creature, preventing the invasion. Then the crystal deposit is also destroyed to prevent creatures from being released in the future.