1. Characters
    1. Barton
    2. Gerry
    3. Marilyn
    4. The Captain
  2. Themes
    1. Value of human life
    2. Law
    3. Humanity
    4. Nature/Fate
  3. Settings
    1. Earth
    2. The frontier of Space
  4. Literary devices/Imagery
    1. Data/numbers
    2. The cold void
    3. Dusk on the planet