Still on the trail of drug kingpin Ronnie Vance, Dr. Keel goes undercover to join Vance's gang at the suggestion of secret agent, John Steed. Threatened with death from a narcotics-laden hypodermic, Vance confesses to the murder of Keel's fiancée. Much to Steed's delight, Keel agrees to remain as his permanent partner. This episode introduced Ingrid Hafner in the semi-regular role of special agent Carol Wilson. Written by series stalwart Brian Clemens, "Brought to Book" was originally telecast January 14, 1961. ~ Hal Erickson, Rovi