Final appearances for both Harry Sullivan (Ian Marter) and Sergeant Benton (John Levene). Both actors felt let down by this serial, as their once-prominent characters were given very little to do in the plot, and had very little screen time.
John Levene (Benton) has an unceremonious send off as he is knocked out and replaced by his Android Duplicate for the remainder of the Episode, this is the last time he's seen in the series, however Levene would return to Play Benton in the Expanded Universe short film Wartime.
Timing reasons meant that a key scene which would have explained how the Doctor reactivated his android duplicate, as well as accounting for the Kraal invasion armada was cut.
This episode was watched by 11.4 million viewers on its original transmission.