"The Princess of the Atom" by Ray Cummings is a science fiction adventure novel that follows Frank Ferrule, a mail pilot, as he is swept into a crisis involving his missing sister Dianne and the threat of conquest from a world within an atom. The story begins when giant human figures are spotted wading in the ocean off the coast of Maine. Frank, flying a patrol, witnesses one of these giants near his family's summer home on Bird's Nest Island. His father and brother Drake receive a cryptic midnight visit from a strange man who warns them about Dianne and tells them they will never see her again. The visitor is physically odd, unfamiliar with chairs and doors, and Drake later recognizes his accent as identical to that of Dianne's companion Ahlma. Dianne had vanished five years earlier. She now reappears on Bird's Nest Island as a figure only inches tall, accompanied by tiny companions. She is able to grow back to normal size using a drug that contracts or expands the cells of the body. Frank and Drake learn that Dianne is not their biological sister but was born a princess in a civilization existing within a single atom of rock buried on the island. Her parents had spirited her into the larger world as an infant to save her from a usurper named Togaro. Togaro has since learned to travel between sizes and has been exploring the outer world, planning to use an army of followers to conquer Earth by appearing as giants and overwhelming its nations. Dianne has come back to enlist her adoptive family's help. She asks them to secure the rock fragment containing her atom, guard it, and use it as a bottleneck through which Togaro's forces must pass, allowing them to be killed as they emerge at small size. A spy in the house turns out to be Togaro himself. Frank and Drake briefly pursue him into smallness but fail to capture him. Togaro physically threatens the family before escaping. Father and Frank establish a heavily guarded room at King's Cove with the rock fragment under constant watch. A young man named Alt eventually emerges from the rock bearing a message from Drake, who has spent the intervening year inside the atom with Dianne, learning her world and working to prevent Togaro's expedition. Frank takes the diminishing drug and travels with Alt into the rock, journeying through a progression of increasingly strange environments, descending from the scale of molecules through atomic space and eventually into the astronomical reaches within a single atom, where Dianne's planet Mita orbits its sun. Frank discovers Togaro has stowed away on their vessel. Togaro captures Dianne, kills a guard, and locks himself in a cabin with her, threatening to destroy the ship if attacked. Frank secretly shrinks himself, climbs onto Togaro's belt, rides him off the ship when Togaro makes his escape upon landing, and infiltrates the Togarite encampment. Meanwhile, Togaro executes his long-planned act of vengeance against the people of Mita who rejected him. Using his enormous ship, he disrupts the planet's orbit and sends it falling into its sun. Ten million people perish. Drake and Ahlma manage to evacuate roughly a hundred and ten thousand survivors in their own vessel before the planet is destroyed. Frank rescues Dianne from Togaro's camp by attacking Togaro directly, stunning him with a rock. Dianne and Frank escape into smallness and begin the journey upward toward the outer world. Drake, Ahlma, and Alt, traveling separately with the Mitan survivors, converge with them near the surface of the rock fragment. The five reach the top together, only to discover the rock has been stolen from Frank's father and is now in the hands of Togaro's agents. They are set upon by Togarite guards. Alt is mortally wounded in the fight, but the guards are overcome. The survivors then face the task of escaping the rock, warning Frank's father, and managing the safe exit of the Mitan refugees, all while evading the Togarite force that is still climbing upward toward the outer world. The narrative closes with the characters poised at the surface of the rock, preparing to signal Frank's father and confront whatever has happened in the outer world during their absence, their mission incomplete but their essential group reunited.
By Ray Cummings · First published 1929 · Genre: Science Fiction, Adventure, Romance · 34 chapters