Appearing in "Suddenly...the Sub-Mariner!"
- Tony Stark (Mentioned)
- Mad Thinker (Mentioned)
- U.S. Air Force
- Numerous unnamed Atlanteans
- Lord Vashti
- United States Naval Officers
- Good King Wenceslas (Mentioned) (Topical reference)
- Devil (Invoked)
- Rare seaweed
- Lord (Yahweh) (Invoked)
- Red Skull (Mentioned)
- Triton (Invoked)
- Zeus (Mentioned)
- Pan (Invoked)
- Mole Man
- Various unnamed Moloids
Races and Species:
- Human-Olympian Hybrids
- Mutants (Mentioned)
- Atlantean-Human Hybrids
- Ants (Mentioned)
- Cows (Invoked)
- Prime Marvel Universe
- Heaven (Invoked)
- Olympus (Mentioned)
- Hawkeye's Bow and Trick Arrows
- Gilligan's Island (Mentioned) (Topical reference)
- Captain America's Shield
- Cosmic Cube
- Bio-Synthetic Wings
- X-76 Verti-Jet (First appearance)
- Nuclear Sub
- Avengers Aero-car
- Levitation Ray
Synopsis for "Suddenly...the Sub-Mariner!"
The Scarlet Witch collapses from stress sustained in their most recent battle (last issue). Elsewhere, the Black Widow steals an experimental jet from General "Thunderbolt" Ross.
The Sub-Mariner attacks a submarine which has been destroying underwater wildlife. He then decides to attack the base it came from. The Avengers receive a call from Captain America warning that a dangerous item called the Cosmic Cube has been seen near the base and the Avengers should secure it.
While Quicksilver stays with his recovering sister, the other Avengers accompanied by Hercules journey to the base and battle the Sub-Mariner. Just as the Avengers are on the verge of defeating Namor, Hercules unwittingly mentions the Cosmic Cube to him. The Sub-Mariner (who had located the Cube earlier but was unaware of its abilities) flies away but returns with the Cube and the battle begins again. Namor is beaten, however, when he loses contact with the Cube, and it is lost down a crack in the ground which seals itself after.
Sometime later, the Mole Man finds the Cosmic Cube but throws it away, dismissing it for a useless bauble.
- Hawkeye, Goliath, Wasp, Quicksilver, Scarlet Witch, Hercules and the Black Widow were all seen last issue in Avengers #39.
- The Sub-Mariner was last seen in Tales to Astonish #91, where Namor battled Attuma and Byrrah.
- Page 1: The damage caused to the Avengers Mansion occurred during their battle with the Triumvirate of Terror in Avengers #39.
- Page 2: The reverse Whammy that Hawkeye mentions is a recounting of how Piledriver of the Triumvirate of Terror managed to redirect Scarlet Witch's hex powers to her in Avengers #39.
- Page 3: Quicksilver relates to Hercules how he and his sister were chased out of their hometown for being mutants (In (Uncanny) X-Men #4) and how they came to join the Avengers (in Avengers #16).
- Although she is shown stealing a jet, the Black Widow is taking part in a secret S.H.I.E.L.D. mission (since Avengers #38) of which she has been branded a traitor for stealing submarine plans (Avengers #39).
- Page 4: General "Thunderbolt" Ross makes an appearance. He was last seen in Tales to Astonish #91 witnessing the Hulk's battle against the Abomination and exclaims that it's bad enough he has to worry about the Hulk, whom Ross has been hunting since Hulk #1. We see Ross again in Tales to Astonish #92.
- Page 8: Cap radios in to the Avengers, who remark about media reports that he has joined forces with the Red Skull (which is all part of an elaborate plot in Tales of Suspense #90).
- Page 9: Cap warns the Avenger of the potential danger of the Cosmic Cube and tells the Avengers to retrieve it. The Cosmic Cube was created by AIM and used by Red Skull who tried to use its powers to conquer the world in Tales of Suspense #80. The Cube was lost at sea in Tales of Suspense #81.
- Goliath mentions that Hawkeye used to be Captain America's biggest critic. Cap and Hawkeye's rivalry for team leadership took place between Avengers #18-29.
- Page 11: Goliath's last encounter with Namor was back in Avengers #3-4, in which the team battled Namor and the Hulk (In Avengers #3) and were saved from being turned into stone by Captain America because of one of Namor's revenge plots (in Avengers #4)
- Page 13: Namor mentions Triton, the son of Poseidon and Greek god of the sea.
- The Cosmic Cube is not seen again until Captain America #114.
- Hawkeye, Goliath, Scarlet Witch and the Wasp all appear next in Strange Tales #156.
- Quicksilver and Hercules appear next in Avengers #41.
- Namor appears next in Tales to Astonish #92.
- Roy Thomas claims that this single story more than any other led to him becoming Marvel's editor-in-chief and Don Heck to becoming the regular artist for the Sub-Mariner in a few years.
- Don Heck takes a break from regular penciler so he can work on the first annual for the Avengers.
- references: Avengers #39, Avengers #38, Tales of Suspense #90, Tales of Suspense #80, Tales of Suspense #81, Avengers #3, and Avengers #4.