This episode in the five-part story arc has appearances by three of the actors who played Special Guest Villains on Batman (1966)--Cesar Romero (The Joker), Burgess Meredith (The Penguin) and Walter Slezak (The Clock King). This was the only one of the five shows in the storyline not to include Diane McBain who on "Batman" had played both The Mad Hatter's assistant Lisa and Pinky Pinkston in the two-parter featuring the Green Hornet and Kato.
Eric Braeden (normally billed as "Hans Gudegast" at the time) has an uncredited part in the raid of Count Solanti's villa. He is the German soldier who asks the Lieutenant why they are taking the art objects to sell.
The windmills shown to suggest that the hero had entered the Netherlands were part of the Kinderdijk collection of windmills in Molenwaard, east of Rotterdam in the province of South Holland. This is a designated World Heritage Site.
The 77 Sunset Strip theme song is not played at the beginning or end of the program.