Sentenced to hard labour on a scorching penitentiary-world after being arrested for (allegedly) assisting an escaped convict (Michael Conrad in 'proto-Planet of the Apes make-up'), Smith and West discover that they are pawns in the prison-warden's plot to solve a major deutronium heist. While the episode is full of campy humour (primarily revolving around the robot baking 'escape-cakes' for his incarcerated friends) and the usual cheap-looking, albeit colourful, props that come and go in puffs of smoke, there is a bit more to the story than in previous LiS outings and Conrad's belligerent snouty 'Creech' is one of the series' better guest-aliens. By this point in the show's trajectory, Jonathon Harris' popular 'Smith' character had been long been reduced to incompetent, greedy, duplicitous, and self-centered comic-relief, but in this story he hits both a new low (falsely accusing Major West of assisting the convict) and an unexpected high (refusing to leave an injured West despite the promise of wealth and freedom). The image of the three prisoners sitting around a block of ice cooling their hands was one of the series' better sight-gags. Far from great sci-fi but still fun to watch (especially for those of us who remember loving the show more than half a century ago).