A century ago the long-running conflict between two alien civilizations ended when both of them colonised the same distant planet, becoming instead a shining example of inter-species cooperation and coexistence. Now an investigation headed by Kyle Riker - estranged father of Commander William Riker - has revealed how fragile their hard-won paradise is. Within a few generations, a virus indigenous to their colony planet of Delta Sigma IV will wipe out all its inhabitants. Faced with this threat