A legendary Jack the Ripper-type killer named the Gaslight Ghoul has apparently returned from the dead. Using the London fog as his cover, the Ghoul is systematically bumping off members of a world disarmament conference. Steed and Tara investigate this phenomenon, only to find themselves on the venerable murderer's hit list. Written by frequent Avengers guest star Jeremy Burnham, "Fog" made its British TV bow on March 12, 1969; it had previously aired in America that same year, on February 17. ~ Hal Erickson, Rovi