The Forbidden Zone was a 4-issue comic mini-series that ran from December 1992 to March 1993. The series was published by Adventure Comics, an imprint of Malibu Graphics, and was written by Lowell Cunningham. It appeared six months after Malibu's regular Planet of the Apes comic had ceased publication, and as such it represented the company's last association with the franchise, and also the last Apes comics until Dark Horse Comics launched a new line on the back of the 2001 re-imagining. The artwork of Leonard Kirk was amongst the best examples of Planet of the Apes comic-book art, with - unusually - accurate representations of the ape species in terms of comparative size and shape and facial features.
The story was set some centuries after the time of the main series from Malibu Graphics - one character deduces that humans must have been made primitive outcasts in the era of Alexander and Jacob, rather than always having been animalistic (which is true, but ignores the conclusion of that story where Jacob welcomes Simon and Anne into Ape City). In this time, the ape-only city is led by the female chimpanzee Councillor Zoe, with General Brak as head of the gorilla military. His insubordinate junior, Colonel Arvo, has an intense hatred for humans and spends his spare time hunting them in their forest home. Arvo's son Julius, however, is a very different gorilla, and he leads an "exploratory expedition" of chimpanzees into the Forbidden Zone, where they find remnants of a human civilization, much to their surprise.
Meanwhile, the authorities in the mutant remnants of New York led by Lord Kolp have condemned their senior colleague Mendez Ten to death for his independent thinking and heresy against their worship of the Alpha-Omega Bomb. He escapes across the Forbidden Zone and both he and Julius find themselves at the mercy of the community known as the Primacy. This settlement was once under the jurisdiction of Ape City, but the spread of the radioactive wastelands cut off communications between the two towns. Primacy has maintained and developed the ideas of human integration that Ape City has turned it's back on. Primacy is led by the chimpanzee Lawgiver Dogen, but many of its leading citizens, such as security chief Pell Shea, are speaking, intelligent humans, though it is not without some discontent from certain gorillas.
Lord Kolp decides to dispatch his army under General Jaekel when he discovers that Mendez lives, just as Colonel Arvo tries to hunt down his son to prevent his heretical discoveries from spreading. Using the advice of Mendez and Julius, Pell Shea is able to maneuver the two armies into wiping each other out, thus ensuring the safety of Primacy. Kolp is content that the ape army has been neutralised and the "unevolved" mutant soldiers (they have no telepathic abilities) have been culled. Meanwhile, Zoe is satisfied that the truth about human heritage will remain hidden from the wider ape population. Mendez and Julius are welcomed as Primacy's newest citizens.