When piloting his SHADO Interceptor escorting the Venus probe, Regan fails to destroy a UFO that leaves Earth carrying his wife.
Describing the episode as a "grown-up drama", he praises the realism of its Moonbase scenes (with their "constant undertone of strain and weariness"), as well as its affirmation of Straker's "fallibility" as SHADO leader.
Fryer also compliments Sheybal's performance as Dr Jackson and Kanner's "brilliant, highly detailed" portrayal of Regan's instability.
[5] John Kenneth Muir criticises some aspects of the plot, arguing that SHADO is too trusting of the clearly affected Regan and careless in allowing an unknown cat to roam its control centre.
However, he praises the cinematography of the seance and abduction scenes, also calling the episode "gloriously filmed" and "one of the most stylishly presented in terms of mise-en-scène".