The Shaper Captain-Doctor Simon Afriel, a passenger in an Investor ship, arrives at an asteroid in another solar system to study a colony of a non-intelligent species known as the Swarm. Their society has an insect-like hierarchy with a queen and different castes, and also hosts some degenerated alien species known with a common name as symbiotes which live as parasites or in commensal relationships with the others. Afriel plans to stay for two years and study it, together with another Shaper called Galina Mirny who was already there. Their intentions are partly to prevent the Mechanists from benefiting from it, and partly to find a way to use the hive pheromones to control and manipulate the species, so they can establish a colony in their own solar system and make them work for them. Once on-board the hive seems to take no notice of the visitors. But when they start to experimenting with artificial pheromones and create a chemical imbalance it triggers the colony's instinctive mechanisms, who recognize it as a sign of the presence of intelligence. The queen lays an egg that develops into a new form which is vigorously protected during development. Once fully developed it is revealed to be a new caste with superior intelligence and a well developed genetic memory derived from multiple species. It reveals that all other castes have only sufficient intelligence to perform their assigned roles, the new form, that refers to itself as Swarm for the lack of a better name, is another reflection of the nest, a specialized form that serves the nest in its assigned role. Swarm acts as part of the superorganism's immune system, and sees unbound intelligence as self-destructive and its presence as a threat to the survival of the colony in the long run. It reveals that humans are not the first race who have invaded the place. Fifteen other intelligent species have done so on precedent occasions and become symbiotes, new members of the colony. When it happens, the representatives of the species that are present are assimilated and become a part of the alien society's genetic collective. Using the same principles as the creation of antibodies through a vaccine, the added genetic material gives birth to numerous superior and loyal individuals of the assimilated race, who will attack and deal with the "infection" the next time their previous kinship arrives and tries to invade Swarm. The symbiotes will then gradually degenerate over the following generations, becoming less and less intelligent until their intellect disappear completely and they become nothing more than genetic memories of their ancestors with no other purpose in existence than survival itself, like DNA remnants from microbes once that invaded a specie's genome. And they will be the only surviving descendants of their race according to Swarm, because racial immortality is only possible without intelligence. Based on Swarm's experiences, a race "infected" with intelligence only lasts for a few thousand years, and is then never heard from again:
