It was first broadcast in the Teledu Cymru region of the ITV network on Friday 22 February 1963.
ABC Weekend TV, who produced the show for ITV, broadcast it the next day in its own regions.
[1] The episode was directed by Kim Mills and written by Geoffrey Orme and Anthony Terpiloff.
[2] A cipher expert commits suicide at an amusement park, however Venus Smith discovers that she has taken a photograph of the man several days later, apparently very much alive.
[3] Julie Stevens sings There's Nothin' Like Love from the film My Sister Eileen and I Know Where I'm Going from I Know Where I'm Going!