Incredible! Your genius, Professor, will give me control of the world's monetary system! START THE MAGNET! 
Blackhawk #123 is an issue of the series Blackhawk (Volume 1) with a cover date of April, 1958.
Synopsis for "The Underseas Gold Fort"
Killer Shark uses a large, shark-shaped submarine to steal an inventor's giant magnet that can pull gold from sea water. The Blackhawks fail to stop him, so to track him, they melt down all their trophies and use the gold to plate the bow of the Hawksub. The gold magnet draws the gold plated sub to it, and the Black Knights use the gold Killer Shark has accumulated to smash the glass walls of his undersea control room and rescue the inventor.
Appearing in "The Underseas Gold Fort"
Featured Characters:
Antagonists:
- Killer Shark
- his pirate submariner crew
Other Characters:
- Professor Charles Renault
Locations:
- Renault's Seaside Laboratory
- Blackhawk Island
- South Atlantic Ocean
- Killer Shark's Undersea Gold Fort
Items:
- Renault's Gold Magnet
Vehicles:
- Blackhawk Lockheed F-90Cs
- "North Star" freighter
- Hawksub
- Shark Sub
Synopsis for "Mystery on Top of the World"
An elaborate riddle left by a former Nazi pilot, who had fought the Blackhawks back in WWII, now leads the team into the Swiss Alps, in search of gold stolen by the Nazis during the war. Another ex-Nazi, Von Kauptner, is also after the gold and uses jet-powered snow saucers and jet skis to fight the Blackhawks. Despite their incredible equipment, they are out-maneuvered and out-fought by the Blackhawks. The Squadron recovers the gold and returns it to its rightful owners.
Appearing in "Mystery on Top of the World"
Featured Characters:
Antagonists:
- Von Kauptner (former Nazi Gestapo chief)
Other Characters:
- Kurt Helner (former Nazi air ace) (Dies)
Locations:
- Frankfurt, Germany
- Blackhawk Temporary City Barracks
- Alps, Switzerland
Vehicles:
- Blackhawk Lockheed F-90Cs
- Von Kauptner's Snow saucers
- Von Kauptner's jet skis
Synopsis for "The Human Rocket"
Martians kidnap Blackhawk and send him into space in a transparent rocket to their "invasion asteroid in orbit." The rest of the team must join him or he will be killed. On the asteroid, the Blackhawks discover that the invasion is the work of renegades, and enlist the aid of good Martians to stop it.
Appearing in "The Human Rocket"
Featured Characters:
Antagonists:
- General Tang (renegade Martian)
- his army
Other Characters:
Locations:
- Blackhawk Island
- Invasion planetoid in space
Vehicles:
- Blackhawk Lockheed F-90Cs
- Martian rocket ships
Notes
- Mystery on Top of the World
- This story shows the Hawk Jets equipped with skis. How they flew in this configuration is not explained.
- Human Rocket
- Martians look just like green skinned bald headed humans.
- Also appearing in this issue of Blackhawk were:
- Full-page ad for that month's issue of Challengers of the Unknown #1.
- Shorty by Henry Boltinoff
- Peter Porkchops: "The Secret of the Happy Pig" (1 page PSA, from National Social Welfare Assembly)
- "Skywatcher's Triumph" (text story) about amateur astronomers hunting comets and how to report finding one.
- Peter Puptent, Explorer by Henry Boltinoff
Trivia