Although they had significant speaking parts, for some reason the characters of Latymer (Anthony Bailey), John Jerry Patterson (Bruce Boa) and The American (Kenneth Nelson) were not credited.
Writer Peter Hammond (aka Peter J Hammond) asked for his name to be removed from the credits because he wanted to dissociate himself from certain changes that were made to his script by other people. Consequently he is listed in the credits under the pseudonym James McAteer.
Martin Shaw and Ralph Michael previously worked together in the first series of Doctor in the House