At the time, Gough was married to Anneke Wills who would shortly join the Doctor as companion, Polly. Gough would also return to Doctor Who as the Time Lord, Chancellor Hedin, in Arc of Infinity.

Although not originally intended to be a new companion, Jamie McCrimmon joins the Doctor, Ben and Polly in the TARDIS at the end of the story. Script editor Gerry Davis and producer Innes Lloyd ...