This episode was wiped by the BBC and no copy of it is known to exist.
Although Douglas Camfield would go on to become the most prolific director of Doctor Who (1963) episodes and Dudley Simpson would go on to become the most prolific composer for the series, this episode was actually the last time they worked together on Doctor Who (1963). In future, Camfield preferred to use other composers or stock music.
The next episode, The Space Museum (1965), begins with a brief clip of the finale of this episode, where the time-travellers stand in period costume round the TARDIS console, literally frozen in time (it is confirmed as a clip rather than a restaged scene by an off-camera cough on the soundtracks to both episodes). This is the only known surviving footage from the final episode.
The Doctor tells Vicki that time must be allowed to run its course, as he had previously told Barbara in "The Aztecs".
This episode takes place in Palestine in 1190.