The Possessed

"The Possessed" is a science fiction short story by British writer Arthur C. Clarke, first published in 1953. The concept for the story was suggested by Mike Wilson. Plot summary A swarm of disembodied aliens, whose home world was destroyed, are in search of an animal species which they can inhabit and guide to intelligence. While many, the swarm operates as a single being. They wander the cosmos and growing weary, find a reptilian species that appeared promising but were not as evolved as the swarm would prefer. The swarm debates leaving the planet and continuing the search or leaving a portion of itself behind. It is decided that it would be wise to leave part of the swarm on the planet, where it can watch the hosts evolve until they are ready to properly guide. The rest will continue to travel and will return if they found a better potential home. Each year the swarm-possessed hosts will travel to a certain location on the planet's surface in search of the swarm's return. As much time passes the location sinks into the ocean, however the hosts continue to seek this location out. They continue to guide the hosts' evolution, going from small reptiles to tiny furry beasts that produce live young. During this evolution the swarm portion realizes that they chose their hosts poorly, as their intelligence only diminishes rather than grow, but can do nothing as their strength grows increasingly weaker and they lose parts of their memory. The pilgrimage now becomes a point of desperation, as they hope to get reabsorbed by the main swarm and regain what they have lost. Time continues to progress until all that is left of the swarm is the urge to travel to the set location.