The "gimmick" in this Avengers episode is a rare postage stamp. When a famed stamp collector is killed, Steed and Cathy head to a philatelic convention, where the aforementioned stamp is about to be auctioned off for a ridiculously low price. The convention turns out to be a front for a radical organization bent on taking over the world. Written by Malcolm Hulke and Terrance Dicks, "The Mauritius Penny" made its British TV debut on November 10, 1962; it was not seen in America until February 4, 1991. ~ Hal Erickson, Rovi