Slowly, Jeffrey's dreams, in which he walks on alien worlds, begin to break into his waking world. He stops going to school, and the life of routine that George and Jean had been enjoying comes to an end. Jennifer, since she is younger, advances even faster than Jeff; she can control objects and even draw nourishment by transplanting food from the refrigerator to her stomach. Soon, children all over the world are displaying these strange abilities. No children are spared: "humanity had lost its future, for the heart of any race is destroyed...when its children are taken from it." Finally, Karellen speaks to the world once more.
Karellen reveals the truth: the Overlords were sent by a higher power, which they call the Overmind, to act as "midwives" to the birth of the next stage of human existence. The Overlords were sent because mankind had started to scientifically examine phenomena such as telepathy and extra-sensory perception. If they succeeded in discovering these secrets, Karellen says, they would have become "a telepathic cancer" that would have spread throughout the universe.
But more significantly, Karellen tells the people of Earth that the minds of the Overlords themselves have reached the end of their development. The same is true of humans in their present form, but humans are capable of making the leap to the "next stage." This stage is to join the Overmind, the entity that the Overlords serve. The Overlords believe the Overmind is trying to grow and "increase its awareness in the universe." The change will be swift, in a few years, and destructive. Karellen tells the adults of Earth that "all the hopes and dreams of your race are ended now." The Overlords will soon round up all the children and take them to a protected part of Earth. Karellen can only give the remaining humans only one consolation: that long after the Overlords are forgotten, a part of the human race will still exist—and for that, the Overlords envy humans.
Jeffrey and Jennifer are taken away from the Greggsons. The same happens with children all over the world. The adults who are left either spend their last remaining days traveling the world, or they commit suicide. The people of New Athens decide to annihilate their island with a nuclear explosion, and George and Jean are there when it explodes, in each other's arms.
The truth is revealed: the children of Earth are no longer the children of humanity. They are destined to move beyond their bodies and lose their individuality in the entity called the Overmind. Here, the line between science and myth begins to blur. Author Arthur C. Clarke has confronted the reader with a creature so omnipotent, so amorphous, and so transcendental, that it is basically a form of God. The Overlords' similarity to Satan and his rebel angels becomes even more obvious here, where they are forever denied the divine presence of joining the Overmind. Though they feverishly work to understand the Overmind better, they have no choice but to serve its needs. These chapters are unquestionably depressing. Karellen's reassurances that humanity has given birth to "something wonderful" seem like cold comfort for the eradication of mankind as it once was. The nuclear death of George and Jean is tragic, if somewhat melodramatic.
These chapters also reveal the mythic framework upon which Clarke has hung a science fiction premise. In a way, Childhood's End is nothing less than a depiction of Armageddon. The Devil, or the Antichrist, arrives in the form of the Overlords. The Overlords actually end strife and conflict, rather than bringing it, but they also herald the end of humanity. The screeching of their ships in the atmosphere is the metaphoric call of the trumpet to Judgment Day. But the only people worthy of joining God, or the Overmind, are the children. Clarke has created a science fiction version of Armageddon, with both God and Satan as aliens, and the humans that join "God" are part of an evolutionary development away from Homo sapiens.
It is difficult to determine exactly how far Clarke intended the religious metaphor to go. Certainly, there are some logical flaws in the plot in these chapters. For instance, neither the Overlords nor the narrator attempt to rationally or logically explain what is happening to the children. In a novel where so many characters—particularly the Overlords—cherish science and reason, the transformation of the children is viewed as an almost mystical or magical event. Clarke has often been an advocate of the idea that any technology, sufficiently advanced, will seem like magic to someone who doesn't understand it—for instance, showing a television to a medieval person. But in the case of the Overmind, technology isn't an issue. The Overmind is, in theory, an alien creature, one who crosses the universe in an immaterial form, absorbing other races that evolve into its collective. The entire concept of the Overmind, and the children's transformation, is an idea that edges much closer to fantasy than science fiction. It may be why, in the paperback edition, Clarke added the comment, "The opinions expressed in this book are not those of the author." In Childhood's End, more than in any of his other works (including 2001: A Space Odyssey), Clarke strays from the pretensions to realism for which science fiction usually strives.
This sense of the fantastic is also supported by Karellen's speech. Karellen claims that, if humanity were to use science to discover the secrets of telepathy and extra-sensory perception, they would become a "telepathic cancer" that would cause great problems for all of the universe. There seems to be a number of questions here. First, both the Overlords and most humans in the novel are, like Clarke, great supporters of science, logic, and rationality. But Karellen is essentially telling humanity that the powers of the Overmind cannot be understood in scientific terms—despite Karellen's own admission that the Overlords are trying to decipher the secrets of the Overmind by studying it. Clarke turns his back on his belief that logic and empirical science can provide all the answers—giving Childhood's End a distinct spiritualistic overtone (which may be one of the reasons Clarke later said that the opinions"in the book were not his own). This appeal to mysticism and transcendental nirvana, which is a good description of the children's transformation into the Overmind, is unique among Clarke's books and may be part of the reason why Childhood's End has remained his most popular work. Imagining that there is a God-like force out there, such as the Overmind, just waiting for humanity to attain a level of mental sophistication so that humans can join with it, has all the appeal of believing in a benevolent God that will someday draw mankind into Heaven.
But when one considers the Overmind in a less spiritual and more rational context, the picture becomes more sinister. The Overmind is an alien force that absorbs races into its collective form, eliminating their individuality and destroying their planet in the process. Furthermore, there is apparently no alternative to the Overmind's tyranny, since even the Overlords, who can never join it, must forever do its bidding or be destroyed. One might wonder whether the Overlords might consider allowing a race such as humans to become this "telepathic cancer"—would they really be destructive or would they offer a new alternative, a challenge, to the tyranny of the Overmind? The Overlords have lied to humanity for over a century. It seems entirely fair to question Karellen's use of terms such as "telepathic cancer" and his unquestioned allegiance to the Overmind.