An off-screen narrator takes us to the ocean floor where we look first at sea snails and then at a mother octopus. The sea snails come with and without shells. We see a group of eggs, then they hatch and we watch nearly microscopic larvae. They whir about. The adult has teeth and a long tongue. We watch one maneuver. We then watch an octopus guard her eggs. She will sit there for three months, on alert, eating nothing. Another octopus appears, they fight. The outcome is in doubt.