Martians want to take over Earth, but they don't invade because even their weakest weapons are so powerful that they would destroy Earth and make it useless to them, so they place agitator spies among the population to incite war.; A man becomes ruler of an underground civilization, but when weapon tests for a planned invasion of the surface go awry and destroy his subjects, he finds himself trapped underground with an immortal lifespan due to radiation treatments he has received.; A man sees a black train at midnight which presages his death.; An evil entity gives a struggling artist a hand, which makes the artist paint well, but also commits murders while the artist is asleep.