Directed by Henry Cass Written by Norman Hudis Tom Conway as Tom 'Duke' Martin Michael Balfour as Barney Honor Blackman as Paula Grant / Paula Jackson Brian Worth as Johnny Matlock Bruce Seton as Webb Freddie Mills as Pat Alexander Gauge as MacAllister John Horsley as Michael Matlock Paddy Webster as Diane Grant John Colicos as First Kidnapper Larry Taylor as Second Kidnapper Arthur Lowe as Mitchell Frederick Schrecker as Professor Dohlmann Marla Landi Terry Savarese June Thorburn Paul Carpenter Bob Bartlett Jan Holden Wilfred Fletcher Christine Silver Becky Crumb Ronnie Stevens Charles Farrell Posh Peterson Alexander Gauge Mr. Arnold Nora Nicholson Rachael Crumb Anita Sharp-Bolster Trevor Reid Colin Douglas Martin