"Propellant 23" is the second episode of the second series of the 1960s cult British spy-fi television series The Avengers, starring Patrick Macnee and Honor Blackman. It was first broadcast by ABC on 6 October 1962. The episode was directed by Jonathan Alwyn and written by Jon Manchip White.
Steed and Cathy must retrieve a flask of top secret rocket fuel stolen from a murdered courier at a French airport.