Comic Title: House of Secrets #30
Publisher: DC (National Comics Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: March 1960
On Sale Date: January 21, 1960 Copyright Date January 21, 1960
Source: Library of Congress, Periodicals 1960

Frequency: Monthly
Cover Price: $0.10
Page Count: 32
Editor: Jack Schiff

Title: "The Creature City"
Pages: 9

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

Penciller: Joe Kubert
Inker: Mort Meskin

Feature Character(s)

• Mark Merlin (last appearance in House of Secrets #29; next appearance in House of Secrets #31)

Supporting Character(s)

• Elsa Magusson (last appearance in House of Secrets #29; next appearance in House of Secrets #31)

Villain(s)

• W'Dor (A criminal from another dimension; no further appearances)

Other Character(s)

• The residents of an unnamed city (Willy named; no further appearances)
• Jim and his father (Mark Merlin's neighbors; no further appearances)
• Authorities from another dimension (no further appearances)

Synopsis:
Mark and Elsa travel to a nearby city where the people have mysteriously disappeared. Mark discovers shadow creatures roaming the city. When one of the shadow turns into an alien it fires a weapon that transports Mark and Elsa to an alternate dimension.

Mark and Elsa are briefly separated before discovering the townspeople safe and unharmed. Mark however directs Elsa away from the people. He locates a weapons cache and transports the two of them back to Earth. After they arrive, Elsa's companion reveals that he is an alien who took Mark's form while they were separated.

The alien explains that he is a criminal named W'Dor. Authorities from his dimension followed him to Earth where they evacuated the townspeople to prevent them from being harmed while they recaptured him. When the authorities finally catch up to W'Dor he uses Elsa as a hostage. However, the real Mark Merlin has followed them. He uses the criminal's own form altering technology to capture W'Dor and free Elsa. The aliens then return the townspeople to Earth.