When the rolling thunder of infra-bass first came to their ears, Robert Blake and Helen Lawton were standing on the platform of a New York subway station waiting for the arrival of an uptown express to bear them to their homes. They made a strikingly attractive couple as they stood there. New York had not had time as yet to remove the bronze tan of an outdoor life from Blake's ruggedly good-looking face. His tall athletic figure was still conspicuous for the lithe strength that had made him an A