A horse stable turns out to be the headquarters of a highly sophisticated murder-for-hire service. Hoping to beard the crooks in their den, Steed employs the services of a valuable race horse. Cathy joins in the scheme when she takes a job with a bookmaking operation -- and, in the words of the episode's opening titles, "becomes the favourite for murder." Written by Malcolm Hulke, "The Trojan Horse" originally aired in England on February 8, 1964; American viewers first saw the episode on March 29, 1991. ~ Hal Erickson, Rovi