A rocket ship from Earth that's arriving on Mars; Mars itself.
Three Witches - From Shakespeare's Macbeth, sees the arrival of the Earth rocket.
Captain - Leader of the rocket's crew, plagued by strange nightmares.
Smith - Crewman of the rocket.
Doctor - Crewman of the rocket, puzzled by Perse's death.
Perse - Crewman dead from mysterious causes.
Reynolds - Another dead crewman.
Grenville - Crewman blinded by an unknown force.
Unnamed Vampire - Presumably Dracula, terrorizing the rocket's crew.
Edgar Allan Poe - Author of tales of the fantastic, now leads the forces against the approaching Earth rocket.
Ambrose Bierce - Author of tales of the fantastic, amused by the upcoming battle between the Exiles and Earthmen.
William Shakespeare - Author of tales of the fantastic, now fighting against the Earth rocket.
Algernon Blackwood - Author of tales of the fantastic, assisting Poe in the battle.
Charles Dickens - Author of various literary works who refuses to fight, as he does not believe he should have been exiled in the first place.
Red Death - One of Poe's creations.
A.E. Coppard - Author of tales of the fantastic, helps Poe in the battle.
Arthur Machen - Author of tales of the fantastic, helps Poe in the battle.
Santa Claus - Suffers greatly from the banning of Christmas on Earth.
Edgar Allan Poe, who has been exiled to Mars by Earthian censorship.
The captain of the rocket ship arriving on Mars, haunted by strange dreams.
The captain burns the last copies of various banned books.
The Martian exiles wither away and disappear as the last copies of their books disappear in flames.
The main theme is censorship and the price it exacts on humanity. By reviving the spirits of the authors of the banned works, Bradbury shows how it's not just words but the people behind the words who suffer at the hands of censorship. These exiled authors and their creations fight back, but are helpless to the act which has exiled them in the first place: the very burning of their books.
On Mars, the three witches of Macbeth predict the arrival of a rocket from Earth to Mars. On the rocket, the captain is concerned about the unexplained appearance of a bat and other seeming hallucinations, followed by the death of a crewman, Perse. Perse had complained of pains but the doctor can't locate a reason for his sudden death. The captain discovers another crewman, Smith, had also suffered from nightmares. Further, Reynolds is dead, Grenville has gone blind, and there is no rational explanation for any of this. The captain asks Smith to fetch the two hundred books he had brought with them on their voyage: the captain had taken them with him because he also suffered from unusual dreams of a supernatural nature before departure. He found this unusual, as books about such unusual subjects were all burned a century earlier. The last copies of these works were in a museum vault for historical purposes, and he decided to take them with him on the rocket voyage.
The three witches observe all this and pass along the news of the rocket's imminent arrival to the ones living in The Emerald City. Edgar Allan Poe and Ambrose Bierce are in a tower in the city, discussing how Will Shakespeare is preparing an army to greet the rocket. Poe decides it's time to tell Charles Dickens of what is happening. Bierce wonders aloud what would happen if the Earthians take hold of Mars; Poe assures that they can move to other planets or hope an atomic war brings back a dark age and the return of superstition. Bierce is amused by the confrontation, which angers Poe, who feels unjustly treated by the censors. Algernon Blackwood brings news of the rocket arriving within the hour; the three leave the castle together. Poe has set up his own creations, including the Red Death, for battle, as have the others. They soon arrive at Dickens' place, where different characters from his fiction celebrate Christmas. Dickens has no time for his visitors, however, believing his books were burned by mistake and that he was never a writer of horror like Poe, despite the occasional inclusion of ghosts in his own tales. Dickens asks Poe what they are doing in Mars with their creations in the first place; Poe theorizes that when their works were outlawed a century ago in 2020, their creations called out to them and the only way to save them was to establish a new home on Mars. Now, Earth is catching up and traveling to Mars to claim as its own with their logic and cold science.
Poe and his friends hurry to the midnight shore of the dry sea, where they join A.E. Coppard and Arthur Machen. Machen wonders aloud what will happen when the very last copies of their books are destroyed. They watch Santa Claus, now a thin short man deprived of Christmas, and Poe wonders what Earth must be like without the holiday. Bierce than fades to dust, as his last book is burned. Blackwood thinks it's time to retreat to another planet, but Poe refuses. As the rocket lands, Poe rages against it in fury. He commands the forces of imagination to rush the rocket and bring it down with their bodies.
The rocket lands and the crew steps out, the captain last. They set up camp and burn the last of the books. They hear screams but don't know what it could be. The captain denies hearing anything and when Smith claims he saw the Emerald City of Oz, just like the story he read as a child, the captain orders him to undergo psychoanalysis the next day. The men of the rocket explore the area, but there's no one present besides them.
The authors named in the story are real and several of them were huge influences on Bradbury's writing. As in "Usher II" in The Martian Chronicles, Bradbury seems to single out the literature of the fantastic as being especially prone to censorship. This seems to indicate that Bradbury believes that the true enemy behind censorship is an over-rational view of the world, one that is so logical that it cannot countenance a "wild" imagination.