That stalks the corridors with enterprise. When Captain Kirk and Mr Spock barely survived the mission to Delta gamma 4, the deadly Planet he's beautiful blue flowers destroyed the mind and ravage the soul, chief medical officer McCoy felt something was dangerously wrong, just how wrong, he didn't realize. For when the Enterprise takes on the alien members of a sensitive Federation diplomatic mission, ambassadors are murdered one by one. The angel of death is visiting the ambassadors.