In the indefinite future, artificial intelligence - in the form of mirrors and screens - fulfills the role of parents. The protagonist is a little girl to whom her mother-tablet tells the story of Colombre, a mythological immortal jellyfish. Aquatic, cellular, microscopic and underwater scenes comment on the adventure of the grown girl, determined to transfer her consciousness to the Colombre and thus guarantee the survival of the human race in a world now completely submerged by water.