Waugh's protagonist, the mild-mannered, unassuming Paul Pennyfeather, is a scholarship student kicked out of Oxford and disinherited under false pretenses. Over the course of the novel he bounces around Great Britain and Wales, falling into one predicament after another as he just tries to mind his own business without success.
Waugh delights in tweaking the unearned pretentiousness of the upper-crust and their unshakable, unproven convictions. The Lords and Ladies of the novel are certain their wealth and privilege are the right and proper nature of things, and no amount of evidence to the contrary can penetrate their thick skulls.
The humor is especially wicked while Paul is employed as a schoolmaster at a private boys' school in Wales. The school and its founder aspire to the highest ideals, but in reality serves as a shelter for the lazy, incurious sons of nobility. Waugh's boldness is especially evident in his use of a a boy's unfortunate accident and subsequent declining health as a recurring joke. Waugh is lampooning the unshakable reserve of the elites, and though the joke is rather shocking, it is also shockingly funny.
Waugh is perhaps best known for his serious, Catholic novel Brideshead Revisited, but he was equally proficient at satire, as this fine novel amply proves.