The second of five uncredited appearances in the series by Johnny Rossi, the others being in E2, The Money Game (1959), E18 The Thousand Mile Alibi (1960), E24 Checkmate (1960) and E39 The Absent Assassin (1960).
The second of four appearances in the series by Roland Bartrop, the others being E7, Diamond S.O.S. (1959), E18 The Thousand Mile Alibi (1960) where he reprised his role as Grimod from this and E7, and E27 Trial at Cranby's Creek (1960).
The second of two uncredited appearances in the series by Ned Lynch, the first being in E7, Diamond S.O.S. (1959).
The first of two uncredited appearances in the series by Robert Brown, the other being in E31, A Foreign Body (1960).