Tragedy began as a drama form in Ancient Greece, a story about a good person who makes an error or has a flaw that causes unforeseen ruinous or sorrowful results. The tragic hero should be good, even great and admirable, so his or her downfall will evoke sympathy in the spectators or readers. The cause of the downfall should come from within the character, or the story is a misfortune but not a tragedy: the hero should do something ignorant, mistaken, deliberate, or accidental, or fail to act. Tragedy has withstood a long test of time with many variations, and modern horror stories sometimes follow its pattern.
If you’d like to write a tragedy, here are a few ideas:
• This is a story about a woman who recovers an object she had hidden in a past life, but she can't remember why she had hidden it.
• This is a military SF story about a noble warrior from another planet who arrives during Earth's Cold War and is confused by the Berlin Wall.
• This is high fantasy quest set in several successive centuries about a wizard who attempts to rescue the last unicorn, told from the point of view of the unicorn.
— Sue Burke