The presence of guest star Vera Miles is indication enough that "Affair in T'sen Cha" was the pilot episode of the classic espionage series I Spy. The opening scenes of Morton Fine and David Friedkin's teleplay work overtime to establish the characters of Kelly Robinson (Robert Culp) and Alexander Scott (Bill Cosby), ostensibly a professional tennis player and his trainer, but actually two secret agents for the U.S. government. Kelly and Scott are then dispatched to Hong Kong to investigate the mysterious disappearance of a Chinese train. The trail of clues takes them to an ancient walled city, a tight-lipped missionary schoolteacher (Miles), and a deadly cargo. The solution to the mystery is logical, poignant, and ever so slightly melancholy. Inasmuch as the easygoing rapport between stars Culp and Cosby had not yet solidified in "Affair in T'sen Cha," this episode was held back from TV release until December 29, 1965, by which time the series had "clicked" with the viewing public. ~ Hal Erickson, Rovi