 Director Robin Hardy (I) (qv) originally wanted  Michael York (I) (qv) for the role of Sgt. Howie. When it turned  out he was unavailable, David Hemmings (qv) was considered before  writer Anthony Shaffer (qv) and producer Peter Snell (I) (qv)  recommended Edward Woodward (qv) who had always been Snells first  choice to play the part.