The Watchers are one of the oldest species in the universe and are committed to observing and compiling knowledge on all aspects of the universe. This policy of total non-interference came into existence due to a former, well-meant attempt by the Watchers to bestow advanced knowledge on the Prosilicans, who used the nuclear technology gained to create weapons and destroy themselves. When the Watchers returned to Prosilicus, the survivors blamed them for causing the catastrophe by giving the Prosilicans nuclear technology before they were ready for it. The Watchers then took a vow never to interfere with other civilizations.