(Barbara smiles at Ian.) (Carol and John depart with the Sensorite.) (He holds up the lock of the TARDIS.) (Susan slowly moves over to the Doctor and the second Sensorite turns to the first.) (The lift doors swish open and the Sensorite, the Doctor and Ian get in, but Susan stays a moment.) ENGINEER: Are the hearts of the human creatures on the right or the left side of their bodies, or the centre as in ours? FIRST-SENSORITE: And all are happy. FIRST-SENSORITE: And what is that? Large expanses of space for windows, and a general lack of roofs indicate a desire to maximise the light from the Sense-Sphere's suns, and bear testament to how little free moisture there appears to be on the surface. We have no need to fear them. Well is it? Who ordered this, the city Administrator?
Plan: A: The Doctor; Q: Who travels to the Sense Sphere to cure an illness? A: Susan; Q: Who communicates with the Sensorites? A: the TARDIS; Q: Where do the Doctor, Ian, Barbara and Susan arrive on board a spaceship? A: the ship's human crew; Q: Who is suffering from telepathic interference from the Sensorites? A: an attack; Q: What do the aliens fear from the humans? A: the Sense Sphere; Q: Where is the Sensorites' planet? A: deliberate poisoning; Q: What is the cause of the illness that the Sensorites and Ian have succumbed to? A: another threat; Q: What does the political manoeuvring of the Sensorite City Administrator pose to the TARDIS crew? A: the TARDIS crew; Q: Who is the Sensorite City Administrator trying to discredit and implicate? Summary: The Doctor, Ian, Barbara and Susan arrive in the TARDIS on board aspaceship. Their initial concern is for the ship's human crew, who are suffering from telepathic interference from the Sensorites, but Susan communicates with the Sensorites and finds the aliens fear an attack by the humans and are just defending themselves. Travelling to the Sense Sphere (the Sensorites' planet) the Doctor seeks to cure an illness to which the Sensorites and Ian have succumbed, but finds it has been caused by deliberate poisoning. The political manoeuvring of the Sensorite City Administrator poses another threat to the TARDIS crew as he seeks to discredit and implicate them.