Sweetpea tells the story of Rhiannon, your average girl next door, who is living quietly with her boyfriend and little dog. By day her job as an office manager is demeaning and unsatisfying. By evening she dutifully listens to her friends' plans for marriage and babies. Rhiannon never complains, smiling through it all with reserves of serenity and a sparkling wit. She has become skilled at keeping it together.

Being normal. But behind this mask is a ferocious power lying dormant, and a long-buried secret that Rhiannon wishes she could forget. When a chance encounter with a stranger leads to a shocking act of violence, Rhiannon's mask slips completely and she is forced to confront the darker side she has long kept hidden. The girl everyone overlooks might just be able to get away with murder.