Due to the BBC's policy of junking episodes in the 1970s, this episode no longer exists in the archives. Several clips survive in the form of an 8mm home movie reel shot off a television set. They are: two seconds of The Doctor in Robespierre's office; three seconds of Ian talking in Jules' house just after his planned escape; one second of Ian talking the following morning, hoping he can trust the physician; one second of Susan lying down in the physician's surgery; and three seconds of Susan looking worried as Barbara tries to open the surgery door. These clips are included on the "Doctor Who: Lost in Time" DVD box set released in 2004.
Although a copy of this episode had also been held in Cyprus, it was destroyed in the 1974 Turkish invasion of Cyprus.
This episode takes place in France in July 1794.
This episode was watched by 6.4 million viewers on its original transmission.