Appearing in "On the Brink of Madness!"
Featured Characters:
Supporting Characters:
- Tamara
- Namorita Prentiss
- Neptune (Illusion or holographic simulation)
Antagonists:
- Force (Clayton Wilson) (Full name revealed and first appearance as Force)
Other Characters:
- Orka (Mentioned)
- She-Beast (Virago) (Mentioned)
- Vashti
- Professor Henry Croft (First appearance)
- Dr. Joseph Jennings (First appearance)
- Dr. Hydro (Herman Frayne) (Mentioned)
- United States Navy (Only in recap)
- Triton (Only in recap)
- Fantastic Four (Only in recap)
- Mister Fantastic (Reed Richards) (Only in recap)
- Thing (Ben Grimm) (Only in recap)
- Human Torch (Johnny Storm) (Only in recap)
- Medusa (Only in recap)
- Kamuu (Mentioned)
- Hensel (Mentioned)
- Zalfir (Mentioned)
- Thakkor (Mentioned)
- Four
- Doctor Strange (Stephen Strange)
- Damon Walthers (Mentioned)
- Betty Dean-Prentiss (Mentioned)
- Diane Arliss (Mentioned)
- Defenders (Mentioned)
- Leonard McKenzie (Mentioned)
- Emma
- Harvey
- Leonard Nimoy (Mentioned)
- Lord (Invoked)
- NYPD
- ⏴ Spider-Man (Peter Parker) ⏵ (Cameo)
Races and Species:
- Mutant Atlantean-Human Hybrids (Main story and recap)
- Banari
- Atlanteans
- Hydro-Men
- Humans (Main story and recap)
- Inhumans (Only in recap)
- Fish
- Seahorses
- Olympians (Illusion or holographic simulation)
- Zephyreans
- Gods (Mentioned)
Locations:
- Earthspace (Main story and recap)
- Earth (Main story and recap)
- Atlantic Ocean (Main story and recap)
- Atlantis Empire
- Atlantis (Destroyed)
- Grotto of the Ancients
- Hydrobase
- Atlantis Empire
- North America (Main story and recap)
- United States of America (Main story and recap)
- New York (Main story and recap)
- New York City (Main story and recap)
- Statue of Liberty (Only in recap)
- Manhattan (Main story and recap)
- Baxter Building (Only in recap)
- Empire State University
- New York City (Main story and recap)
- Hudson River
- New York (Main story and recap)
- United States of America (Main story and recap)
- Atlantic Ocean (Main story and recap)
- Earth (Main story and recap)
- Zephyrland
Items:
- Fantastic Four Uniforms (Only in recap)
- Neptune's Trident (Illusion or holographic simulation)
- Force Armor (First appearance)
Vehicles:
- Fantasti-Car MK II (Only in recap)
Synopsis for "On the Brink of Madness!"
Namor returns to his underworld realm to find it devastated in the wake of the nerve gas contamination. Fortunately, his subjects are just in a comatose state and amphibian scientists are eager to help them. Namor takes the scientists to Dr. Hydro's island base and then seeks out Dr. Walthers who has been working on a force field device that can protect Atlantis from any other nerve gas contamination. However, the costumed villain Force stands in his way. Namor drives him off and continues his search for Dr. Walthers.