Mary is a young, unwed girl pregnant with John Alden's baby in Salem, a Puritanicaltown. Believing her lover John was killed during King William's War, she is now faced with the Puritans' stocks and forehead branding, or giving her and John's child to the devil. Having chosen the latter, she marries the town's richest and most influential selectman George Sibley, claiming his wealth and power for herself by enslaving him. Reverend Cotton Mather is trying to stop witches from taking over America by killing them. John returns home to witness a witch-hunt, wherein Mary plans to use the trials to get Puritans to kill each other, allowing her to rule Salem.

When Magistrate Hale discovers that it was Isaac who broke the witches circle, it's up to John to save him. A power struggle arises within the hive, forcing Mary to assert her authority with potentially deadly consequences.