Chain Of Command, Part I

Because of a feared imminent Cardassian invasion, Vice Admiral Alynna Nechayev comes to the Enterprise on the USS Cairo, to replace Picard as its captain by Cairo's captain, Edward Jellico, who immediately makes his mark on crew and ship, tells Troi there's no time for a 'honeymoon' with either for he expects the negotiations with the Cardassians he's charged with to fail and hastily deploys big plans to prepare the flagship for battle. Meanwhile, Picard, Worf and Dr. Crusher have a top-secret mission, to find and sabotage the presumed biological superweapon which can wipe out all life on a whole system prior to invasion. After their training, the trio bribes a Ferengi smuggler ship to reach the suspected Cardassian planet, but by the time they have intruded the subterranean installation... —KGF Vissers