"The Testament of Arkadia" is the twenty-fourth and final episode of the first series of Space: 1999. The screenplay was written by Johnny Byrne; the director was David Tomblin. The final shooting script is dated 5 February 1975, with a revised final shooting script dated 25 February 1975. Live-action filming took place Tuesday 11 February 1975 through Tuesday 25 February 1975.