Richard Fleischer directed this nightmarish science fiction vision of an over-populated world, based on the novel by Harry Harrison. In 2022, New York City is a town bursting at the seams with a 40-million-plus population.
Food is in short supply, and most of the population's food source comes from synthetics manufactured in local factories -- the dinner selections being a choice between Soylent Blue, Soylent Yellow, or Soylent Green.
When William Simonson (Joseph Cotten), an upper-echelon executive in the Soylent Company, is found murdered, police detective Thorn (Charlton Heston) is sent in to investigate the case. Helping him out researching the case is Thorn's old friend Sol Roth (Edward G. Robinson, in his final film role).
As they investigate the environs of a succession of mad-from-hunger New Yorkers and the luxuriously rich digs of the lucky few, Thorn uncovers the terrible truth about the real ingredients of Soylent Green.