Henry A. Perkins, a mild-mannered accountant accidently picks up the wrong briefcase - one full of money. Henry assumes it is illicit cash and he decides to keep it. Knowing that the former owner is probably a villain and must now have his briefcase, he rushes home to book one-way fares to Barcelona – or Bali. His confused wife is preparing for a dinner party – but – instead the evening turns into a frenetic whirlwind of guests, bent coppers, Mr Nasty and . . . .Mr Big