A 'Travelogue', complete with 'American' announcer, introduces the county town of Orbiston Parva and the Despard family, local landowners and proprietors of the local Tranquilax factory, the area's largest employer.

The Rev. John Smallwood, an idealistic idealistic prison chaplain, has been left trussed up in his underwear by the fleeing Convict no. 181, who Smallwood had recommended to be made a trustee. The Governor and the Chief Warder are not unhappy to see Smallwood move to another position.

However, a Church of England filing error sees Smallwood appointed as Vicar of Orbiston Parva, in place of the public school-educated clergyman of the same name who was recommended by Archdeacon Aspinall. The sole person to greet Smallwood in a friendly manner is Matthew, a West Indian dustman. Following a dispiriting tour of the town, Smallwood decides on radical measures and appoints Matthew as churchwarden in place of Major Fowler, a town councillor and local property developer. Smallwood then gives shelter in the vicarage to the Smith family, a tribe of itinerant ne'er-do-wells who have recently been evicted from their latest squat by the Tranquilax factory, which acquired the property thanks to Fowler's generous interpretation of the planning rules.

Meanwhile Lady Despard, the matriarch of the family, is moved by Smallwood's genuine faith and decides to follow his idea of the social gospel; she distributes produce free from her farm, and then sells her Tranquilax shares to fund her Christian generosity. This, Smallwood hopes, will encourage a genuine sense of give and take. But many townsfolk merely take, while the giveaway severely impacts on local small businesses, and the sale of her Tranquilax stock leads to a panic on the markets. Many workers are laid off.

Meanwhile, Convict No. 181 is released and turns out to be one Fred Smith of the local tribe. Increasingly alarmed by the events in Orbiston Parva, Bishop Goodbody and the Archdeacon hire the psychiatrist Dr. Rockerby to examine their problem Vicar, but he manages to interview the wrong Smallwood.

Geoffrey, Lady Despard's son, returns from abroad to discover the family pile housing tramps and the family business on the verge of collapse. He confronts Smallwood and is amazed to discover that the vicar is well aware that the Smith family is sneering at him. The family's sole remaining servant, the seemingly senile butler, Simpson, contrives 'a sign from God', instructing Lady Despard to cut out all charitable acts. Geoffrey, meeting with the PM, agrees for the Commissioners of the Church of England to refinance his factory on the grounds that Smallwood leaves..

On learning that there will be no delivery of food, the townsfolk revolt. Matthew is attacked by teddy boys. He abandons Smallwood and advises the clergyman to also flee. But Smallwood defies the advice of the town's police inspector and faces the people. He narrowly escapes being lynched. The police manage to smuggle him back in the dustcart to the vicarage, where Smallwood finds that the Smiths have departed, taking with them most of the furniture (and the lead from the church roof). At this point Aspinall arrives, with two senior Church officials in tow, to offer Smallwood the Bishopric of 'Outer Space' at the British Rocket Group in the Orkney Islands. Smallwood agrees, but refuses to take part in PR stunts.

Prior to the launch of Britain's first manned rocket, Smallwood inists on counselling the nervous astronaut who claims that the Church rarely practises what it preaches. Smallwood proves otherwise by trussing him up, donning his space-suit, and orbiting the Earth, warbling hymns of love and peace to anyone who cares to listen.