Robert Conrad and Anthony Eisley previously co-starred in the 1959-63 crime and adventure series Hawaiian Eye (1959).
Artemis Gordon does not appear in this episode. Ross Martin appears in credit only as he was recovering from a heart attack.
Robert Conrad went on to play a homicidal health club magnate named Milo Janus in An Exercise in Fatality (1974).
The mortician's name is Swanson; in the previous episode Jim Backus played a mortician named Swanson.
Jeremy Pike's undercover identity, Baron Klaus Esterhazy, is like a play on French Major Esterhazy who was the Dreyfus Affair from 1894 -1906.