John Rogers as Lake; Mary Gordon as Prison Visitor (uncredited); Alan Mowbray as Paul Frank; Ray Milland as Neil Howard; Madge Bellamy as Mrs. Fothergill; Murray Kinnell as Phillips; E.E. Clive as Detective Sergeant Thacker; Claude King as RAF Aerodrome Commander (uncredited); Douglas Walton as Hugh Gray; Walter Johnson as Jerry Garton; Mona Barrie as Lady Mary Bristol; Warner Oland as Charlie Chan; C. Montague Shaw as Doctor (uncredited); David Torrence as Home Secretary; Drue Leyton as Pamela Gray
L. William O'Connell
After receiving congratulations from the Home Secretary for solving his most recent case, Charlie is sought out by Pamela Gray, a beautiful but desperate young socialite whose brother Paul awaits execution for the murder of a weapons inventor. She is so convinced of his innocence that she becomes distraught when she overhears Neil Howard, her brother's lawyer and her fiancee, confide to the detective his belief in his client's guilt. Angered at this disclosure, she returns his ring and breaks off the engagement. Although the execution will take place in 65 hours, Charlie pledges to expose the murderer. All potential suspects are reassembled in the country mansion of family friend Geoffrey Richmond, where the murder took place, as Charlie tries to expose the real murderer before time runs out.