It is 1845, and Martha Morgan, Mistress of Plas Ingli, is feeling her age. She receives warnings that she should 'take care'. Her beloved estate collapses, and she has to call upon her deepest reserves of strength in order to survive. But her misery is lessened when she meets a travelling evangelist on the summit of Angel Mountain. It turns out that the fate of Amos Jones Minor Prophet is inextricably bound up with her own. A single indiscretion in Tycanol Wood splits the community and tests the loyalty of friends and family to the limit, and starts a drift towards the final tragic episodes of Martha’s life.

While Martha is dealing with these personal crises, she is also drawn to help the peasants caught up in the Irish Potato Famine. A shipwreck on the coast near Newport gives her the opportunity to do something practical, but in the process she offends the secret Society of Sea Serjeants. Her family tries to protect her from evil men who are driven by ancient family animosities. But her fighting spirit is stronger than her body, and she takes them on. It becomes clear that Martha will not die in her bed; nor does she, but in the final act of her exciting life there are breathless twists and turns which confound her enemies and leave her undefeated.