Comic Title: House of Secrets #31
Publisher: DC (National Comics Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: April 1960
On Sale Date: February 23, 1960 Copyright Date February 23, 1960
Source: Library of Congress, Periodicals 1960

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

Title: "The Hybrid Monster"
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 #30; next appearance in House of Secrets #32)

Supporting Character(s)

• Elsa Magusson (last appearance in House of Secrets #30; next appearance in House of Secrets #32)

Other Character(s)

• A hybrid monster (no further appearances)
• An unnamed scientist (no further appearances)
• Captain Tobuai (no further appearances)

Synopsis:
Mark Merlin visits the island of New Guinea where he investigates a glowing mountain. Mark and his guide also spot a weird flying creature. They follow it to the lab of an eccentric scientist who is conducting experiments and creating hybrid animals.

Mark is captured by the scientist and strapped to a machine which transfers Mark's intelligence to one of the hybrids. The creature they destroys the lab and escapes. Mark chases the creature around the mountain, but the beast's intelligence allows him to elude his pursuer.

Mark eventually concludes that the creature is gathering supplies and bringing them back to the lab. The creature then causes an explosion which destroys the lab and eradicates the rare radioactive element thiridium which caused the mountain to glow. Mark realizes that the creature sacrificed itself to save the Earth from doom.