 The model shots of Verdain's yacht feature a background painting of Monte Carlo Bay, which was also created by Trim and had previously appeared in the "Thunderbirds" episodes "The Man from MI.5" and "The Duchess Assignment".It would later appear in the "Joe 90" episode "The Race".The incidental music, performed by an ensemble of 16 instrumentalists, was recorded during a four-hour studio session held on 27 August 1967.