 Teenager Doris Bannister (Gigi Perreau) is having a fling with Stefan Riker (Werner Klemperer), a shady East German who is a longtime acquaintance of Doris  step-mother, Lisa Bannister (Osa Massen). One day Doris shows up at Perry Mason s (Raymond Burr) office asking for help. Riker has been murdered, and Doris has global amnesia, or is she faking it?