Dangerous assignments come in pairs when Captain Picard and his crew are confronted with two desperate missions on two different worlds. On the planet Buran, newly linked to the Federation, a mysterious disease devastates the population-and turns them against the visitors from the U.S.S. Enterprise. Meanwhile, on nearby lomides, a renegade Federation observer has disappeared, intent on violating the Prime Directive by preventing a tragic political assassination.

While Dr. Crusher struggles to find a cure for the plague ravaging Buran, Commander Will Riker leads an Away Team to lomides. Their forces divided, Picard and his crew find themselves the only hope of two worlds.