Semyon Lavochkin was one of the most successful Soviet aircraft designers of the piston-engine era. But although he also produced several good jet designs, events always seemed to go against him and none saw real success. In the early 1950s he tried again, one last time. His objective was to make a giant supersonic, all-weather interceptor to defend the Soviet Union against SAC bombers. The result of his efforts was the mighty 250. This video tells its story.