Appearing in "The Summons of Psyklop"
- Avengers (Main story and flashback)
- Captain America (Steve Rogers) (Main story and flashback)
- Goliath (Clint Barton) (Main story and flashback)
- Iron Man (Tony Stark) (Main story and flashback)
- Thor (Odinson) (Main story and flashback)
- Black Panther (T'Challa) (Only in flashback) (Leaves team)
- Scarlet Witch (Wanda) (Only in flashback)
- Quicksilver (Pietro) (Only in flashback)
- Vision (Only in flashback)
- Hulk (Bruce Banner)
- Redwing (Main story and flashback)
- Falcon (Sam Wilson) (Main story and flashback)
- H.P. Lovecraft (Referenced)
- U.S. Air Force
- Mr. Fantastic (Reed Richards)
- Professor X (Charles Xavier)
- Visigoths (Mentioned)
- Dark Gods (Mentioned)
- Louisiana Police (Only in flashback)
- Sonny (First appearance) (Only in flashback)
- N'Baza (Mentioned) (Only in flashback) (Death)
- Odin (Mentioned)
Races and Species:
- Humans (Main story and flashback)
- Hawks (Main story and flashback)
- Dark Gods (Mentioned) (Only in flashback)
- Zombies (Mentioned) (Only in flashback)
- Synthezoids (Only in flashback)
- Elder race of Psyklop (First appearance)
- Giant Slugs
- Rabbits (Mentioned)
- Rats (Mentioned)
- Dogs (Mentioned)
- Insects (Mentioned)
- Fantastic Four Uniforms
- Goliath's Suit (Main story and flashback)
- Captain America's Uniform (Main story and flashback) and Shield
- Iron Man Armor Model 3 (Main story and flashback)
- Mjolnir (Main story and flashback)
- Panther Habit (Only in flashback)
- Quinjet (Main story and flashback)
Synopsis for "The Summons of Psyklop"
With the aid of Reed Richards and Charles Xavier, the military has managed to capture the Hulk with a special device that incapacitates the brute. When the Hulk is finally knocked out, they intend to seal him in a chamber that would constantly keep him sedated with coma-inducing gases. With the Hulk finally knocked out, the military begins to move in and collect the unconscious monster.
Meanwhile, the Avengers Goliath, Iron Man, and Thor have joined Captain America and his partner the Falcon to an island out in the pacific. What brought them there was events that happened days earlier: When the Falcon becomes concerned about a friend who was due to come up and visit from New Orleans didn't show up. Traveling there, they happen to track down Sam's friend to a voodoo ceremony taking place deep in the swamps where the practitioners are showing worship to the Dark Gods. Fighting the Voodoo cult, they find that Sam's friend is among them and all he says over and over is the location of the island in latitude and longitude. Returning to New York the duo would recruit Cap's fellow Avengers to help them investigate, although Black Panther, Vision, Scarlet Witch and Quicksilver opt to stay behind to attend to other matters. On the island, the Avengers stumble upon a gigantic statue of some ancient demon.
While back in the United States, as Reed Richards prepares to put the Hulk into the specially made container, he is shocked to see the Hulk suddenly teleport away. The Hulk has been transported to a secret laboratory on the island the Avengers are exploring by a creature named Psyklop. Psyklop is a member of an ancient insectoid race that existed before man and worships the Dark Gods and hopes to take over the world for them.
As the Avengers are faced with a strange monster on the surface, Psyklop prepares to shrink the Hulk down to size, hoping to use his body as a power source to summon the Dark Gods. The Avengers, having fought off the monster outside crash into the lab and begin fighting Psyklop. During the fight, the Hulk is left unattended and the shrink ray trained on him causes him to shrink so small that he vanishes from sight. Furious at losing the Hulk, Psyklop uses a teleportation device to send the Avengers back to New York. The group materializes in the middle of a subway with no memory of the battle they had just had.
The Hulk's fate continues in Incredible Hulk #140...
"The Summons of Psyklop!" A monster from beyond time and space - the final caging of the Hulk - And the eeriest war-of-the-worlds this side of H. P. Lovecraft! Like weird!
- Science-fiction writer Harlan Ellison wrote this issue, and received a very-unusual-for-the-time cover blurb.
- This issue is influenced partly by subjects created by H.P. Lovecraft and the Cthulhu Mythos as a whole:
- The quote on the first page is from the novella "The Call of Cthulhu".
- The interruption by cops (joined by Avengers) of the "voodoo" ceremony in the bayou dedicated to dark gods, is presumably inspired by a scene from "The Call of Cthulhu".
- The ancient pre-human race of Psyklop worshiping dark gods is presumably based on the likes of the Deep Ones and the Serpent-Men.
- The giant slug is stated to have originated from Lemuria.
- The phrase "you have a mouth -- and you must scream!" is a self-reference to Ellison's Hugo Award-winning short story "I Have No Mouth, and I Must Scream".
- Iron Man's reference to once seeing "a layout like this... in a comic-mag at the end of an abandoned subway tunnel" is most likely a nod to the origin story of Fawcett Comics' superhero Captain Marvel (a.k.a. Shazam) from Whiz Comics #2. In that issue, homeless newsboy Billy Batson gains the Capt. Marvel alter ego after following a mysterious stranger to the end of an abandoned subway tunnel where he finds seven statutes depicting the "Seven Deadly Enemies of Man."