The second of three appearances in the series by John Crawford, the others being in E3, The Sleeping Giant (1959) and E31 A Foreign Body (1960).
The second of four appearances as Captain Pagano by George Pastell, the others being E4, The Two-Headed Monster (1959), E18 The Thousand Mile Alibi (1960) and E26 The Girl with Grey Hair (1960).
The second of three appearances in the series by Lisa Daniely, the others being E7, Diamond S.O.S. (1959) where she also played the character Helene, and E29 Slow Boat to Amsterdam (1960).