The novel addresses people's, especially women's, control of their lives, a subject about which Sackville-West was greatly concerned although often pointing out that she did not consider herself a feminist.

She has been the dutiful wife of a "great man" in public life, Viceroy of India and a member of the House of Lords.

Her children plan to share her care between them much as they divide up the family property but unexpectedly Lady Slane makes her own decision, proposing to leave fashionable Kensington for a cottage in suburban Hampstead that caught her eye decades earlier, where she will live alone except for her maidservant and please herself — for example allowing her descendants to visit only by appointment.

Mr FitzGeorge, a forgotten acquaintance from India who has ever since been in love with her, introduces himself and they form a quiet but playful and understanding friendship.

Mr FitzGeorge bequeaths his fortune and outstanding art collection to Lady Slane, causing great consternation amongst her children.

Lady Slane, avoiding the responsibility of vast wealth, gives FitzGeorge's collection and fortune to the state, much to her children's disgust and her maid's amusement.

Sharing much with Sackville-West, Lady Slane explicitly states that she is not a feminist and considers such issues to be questions of human rights, while acknowledging the more difficult position of women.

An acquaintance from Lady Slane's distant past as Vicereine of India, millionaire by inheritance, lover of beauty and fine art.

In 1986 All Passion Spent was adapted into a 3 episode BBC television series starring Wendy Hiller as Lady Slane.

In 2009 BBC Radio 4's Woman's Hour broadcast a five-part adaptation starring Honor Blackman as Lady Slane and Mr FitzGeorge played by Alec McCowen.