When her brother, Edward, announces his engagement to Elizabeth, Mariah sees no reason not to rejoice. It transpires, however, that her new sister-in-law and mistress of Addison Terrace, Reading, has plans, not simply to alter the appearance of the impressive town house but also to eject Mariah and her elderly great-aunt from their home.

The frenetic social scene of late Georgian England takes Mariah to London for the season and amidst the rounds of outings, balls and evening engagements the prospects of marrying eligible young gentlemen are weighed up. The pressure of social convention for young ladies of standing to marry is ratcheted up and an unwelcome match looms. A mysterious misunderstanding causes an influential family to take offence at Mariah and places her marriage hopes in jeopardy. The deduction that Elizabeth's jealous scheming is responsible is never far from Mariah's mind as the tension between the two mounts.