An exotic yet harmless rhynal virus suffered by the First Officer of the U.S.S. Lantree NCC-1837 two days before the ship's crew docks at the Darwin Genetic Research Station on Gargarin IV. Harmless, that is, until it is genetically mutated by an aggressive antibody from the Darwin Station's "superchildren," creating a hyperaging disease that kills the Lantree crew and infects the station staff. The officer's illness is the only one recorded among the ship's 26 crew members since their last duty cycle began eight weeks before.