Matthew Hopkins is perhaps the most notorious, certainly the most productive, witchfinder that England ever boasted. In eighteen months between 1645 and 1646, he was responsible for the condemnation and execution of at least 230 witches in south-east England and East Anglia. His victims were for the most part elderly women, though men too, even respected clergymen, faced trial and capital punishment for performing witchcraft and making covenants with Satan. Hopkins had appointed himself Witchfinder General by order of Parliament but his reputation as a local hero became tarnished by his use of excessive torture, too many false accusations, and confessions obtained by dubious means.

His death is somewhat mysterious. He died while still quite young, possibly after having been accused of witchcraft himself and executed. Craig Cabell, already a noted biographer of such contemporary students of the occult as Dennis Wheatley and James Herbert, uses the copious extant records and Hopkins's own writings, to create a richly detailed picture of a man and a society obsessed with magic, devil worship and the powers of darkness. He provides the first full modern biography of a man who turned his undoubted energies and gifts into a streamlined, and profitable, killing machine.