doubleindemnity MacMurray/Stanwyck film Life insurance policy provision Life insurance clause specifying twice the payment for certain situations Life insurance clause Insurance for an identical twin? Insurance clause Certain insurance claim Insurance provision 1944 thriller with Fred MacMurray and Barbara Stanwyck Billy Wilder film: 1944 James Cain novel Repeated hostility, switching pair of characters around in film Done by trains with "unlimited" return after unplanned departure in USA