New England’s Puritans were devoted to self-scrutiny. Consumed by the pursuit of pure hearts, they latched on to sincerity as both an ideal and a social process. It fueled examinations of inner lives, governed behavior, and provided a standard against which both could be judged. In a remote, politically volatile frontier, settlers gambled that sincerity would reinforce social cohesion and shore up communal happiness. Sincere feelings and the discursive practices that manifested them promised a safe haven in a world of grinding uncertainty. But as Ana Schwartz demonstrates, if sincerity promised much, it often delivered more: it bred shame and resentment among the English settlers and, all too often, extraordinary violence toward their Algonquian neighbors and the captured Africans who lived among them. Populating her “city on a hill” with the stock characters of Puritan studies as well as obscure actors, Schwartz breathes new life into our understanding of colonial New England.