The Doctor, Ian, Barbara and Susan arrive in the TARDIS on board a spaceship. 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.
Encompassing three hugely popular double acts, The Crazy Gang were one of Britain's best-loved, most enduring variety troupes – their antics delighting audiences for over three decades from the early 1930s and their career taking in numerous Royal Command performances. Their efforts to save a struggling circus provide the laughs in this uproarious comedy, also starring Goldfinger icon Shirley Eaton and featuring Flanagan and Allen's rendition of their greatest hit, Underneath the Arches. The Crazy Gang have been jacks-of-all-trades with Joe Winter's Monster Circus for almost as long as Joe has been on the road, and they're still hoping for a big break. But Joe has hit hard times: his equipment is mortgaged, most of his acts have deserted him and even the elephants have walked out. So the Gang set about finding a way to save the circus... and come up with a typically novel solution!
