 Manhattan press agent Sidney Falco ( Tony Curtis ) has been unable to gain mentions for his clients in J.J. Hunsecker 's ( Burt Lancaster ) influential , nationally syndicated newspaper column of late because of Falco 's failure to make good on a promise to break up the romance between Hunsecker 's younger sister Susan ( Susan Harrison ) and musician Steve Dallas ( Martin Milner ) , an up @-@ and @-@ coming jazz guitarist . 
