It consists of two parts: the first is about the last months in the life of John Keats and his encounters with the Roman (dialectal) poet Giuseppe Gioacchino Belli.

In Part One, Keats has various adventures, meeting Belli in the Sistine Chapel, Pauline Bonaparte (sister of Napoleon) in the Pincio, and a Roman man of letters named Giovanni Gulielmi.

Part Two consists of about seventy (from a total of 2,279) amusingly blasphemous sonnets by Belli, purportedly translated by one Joseph Joachim Wilson, a descendant of Gulielmi.

An elaborate passage describes how the Italian Gulielmis were transformed into English Wilsons "during a wave of anti-Italian feeling occasioned by alleged ice-cream poisoning in the 1890s in the Lancashire coastal resorts of Blackpool, Cleveleys, Bispham and Fleetwood".

Belli was a real person but Giovanni Gulielmi and his descendant Joseph Joachim Wilson are fictional.