J. B. Priestley employs the arrival and departure of the mysterious Mr. Golspie as the frame in which to paint a panoramic portrait of London life in the midst of the Great Depression. When James Golspie, sole agent for a Balkan firm that cheaply produces veneers and inlays, arrives in London to find an outlet for his business, he is intrigued by the name Angel Pavement, a cul-de-sac in the heart of the business district of London called the City, and moves in on Twigg & Dersingham, a firm located there that is experiencing a sales decline which is only partly the result of the unfavorable economic climate. That Howard Dersingham, who fancies himself a gentleman, is not cut out for the business world enables Golspie to manipulate him with ease.

Whatever Golspie’s original intentions toward the firm, a disastrous dinner party at the Dersingham home, at which Golspie and his uninvited, late-arriving daughter Lena are rudely made to feel intruders among guests with pretensions to a higher social class, seals the fate of Twigg & Dersingham. Golspie convinces Dersingham to pay him his unusually high commissions in advance as orders pour in without informing the unwitting head of the firm that the suppliers of the veneers have raised their prices by as much as seventy percent. With contracts signed to supply customers at lower prices than it can in fact afford to offer, Twigg & Dersingham is ruined as Golspie and his daughter quietly sail for South America and new worlds to conquer, more fools to dazzle and destroy.

Within the frame of an intricate business swindle, Priestley explores the mood and values of a Britain that has gone awry after World War I. Traditional English values of hearth and home have been lost as a younger generation adopts the surface values of Hollywood films, falls prey to foreign, sometimes criminal, business practices, and desperately seeks a good time and easy money among the faceless multitudes wandering aimlessly along the overcrowded thoroughfares and dismal back streets of a bleak and unwelcoming city. It is the lives of the firm’s employees that become the focus of the novel. As the fortunes of Twigg & Dersingham rise and fall, so too do the hopes and dreams of its bookkeeper, secretary, and junior clerk.