Very unused to mingling in society, but seeking her place in it, Miss Mackenzie moves to a town called Littlebath (modeled after Cheltenham, Gloucestershire), and joins a group of Evangelicals centered around the popular local pastor Mr. Stumfold and his wife.

One is Samuel Rubb, the business partner of her surviving brother, Tom Mackenzie; another is Mr. Maguire, Mr. Stumfold's curate, who is only interested in securing her wealth; and the third is her cousin, John Ball, a widower with a large family to support.

Mr. Maguire, unwilling to believe Miss Mackenzie has lost all her wealth, starts writing articles in an Evangelical newspaper about a Lion and the Lamb he intends to devour.

The story of "the Lion and the Lamb" is picked up by newspapers across the country, causing John Ball much agony, even though public opinion is on his side.

[1] Though critics like the young Henry James found Miss Mackenzie vulgar and prosaic, others have found interesting aspects to the novel, including the fidelity and sympathy with which Trollope depicts the lives of ordinary characters like Miss Mackenzie and Mr. Rubb, and his satirical treatment of Evangelical society, of its representatives in the novel, Mr. and Mrs. Stumfold, and of the group gathered around them.