The first nine episodes of season one were made in black-and-white, and used a different titles and credits sequence compared with the later color episodes in this season; even for the color episodes, the introductory Thames caption (the iconic London skyline and river montage) was in black-and-white.
Patrick Mower said that he was brought into this show to give it a bit more zest.
It was supposed to have been heralded as the new kind of British television. Unfortunately, this show wasn't as successful as "Euston Films" hoped.
The original series consisted of twenty-seven episodes, and these were broadcast by Thames Television in 1969 and 1970. Derren Nesbitt was the only cast member to appear in all of them.
George Sewell said that owing to the fact that this show was shot entirely on film, there wasn't much time for any rehearsals. The cast used to read through their scripts before going for a take.