The third in Douglas Watt’s series of murder mysteries set in 17th-century Scotland and featuring lawyers John Mackenzie and David Scougall takes place as William of Orange is on the verge of usurping James VII and II. The streets of Edinburgh are aflame with Protestant riots and denouncements of popery. When a Catholic fanatic murders a nobleman and ignites a chain of killings, Mackenzie and Scougall are called in to investigate. Scougall has got himself involved in a mercantile project with an old acquaintance and finds himself consorting with a secret alliance of Presbyterians keen to foment revolution, but soon this ruthless group become victims and suspects too. Despite his banal prose style, Watt sets up a thoroughly intriguing narrative with a good spread of characters and keeps the reader guessing if political or religious hands are behind the murders. Sadly the denouement is a disappointing blend of gratuitous horror and amateur Freudian dramatics.