The Enterprise discovers a lifeless Federation research vessel, orbiting a planet hidden behind a mysterious energy shield. Over the strong objections of his senior officers, Captain Picard and an away team beam over in search of the missing crew -- And vanish. But soon his captain's disappearance is not the only problem facing Commander Riker. For a mysterious disease has begun ravaging the "Enterprise crew. Now Riker must unravel the secrets of the planet below in order to rescue Picard -- and prevent the starship's destruction.