This second volume of Algernon Blackwood's complete short stories includes the six stories he wrote about the psychic detective John Silence. Only five of them were collected in John Silence-Physician Extraordinary (1908), which became a bestseller and allowed Blackwood to spend the next six years in financial security. The John Silence stories set the pattern for the psychic detective, and dozens of authors have imitated the detective's pursuit of the strange and supernatural.

For Blackwood, the John Silence stories allowed him to express some of his most deeply held beliefs as well as to adapt elements from his own life. "Secret Worship" is based on Blackwood's time with the Moravian Brotherhood in Germany. "Ancient Sorceries" is a haunting tale of metempsychosis, where the inhabitants of a French town turn into cats at night. "The Camp of the Dog" is a powerful werewolf story.

Other stories are innovative ghost stories or tales of peculiar happenings in ordinary settings. Many of these appeared in leading British periodicals of the day, but not all of them were gathered into Blackwood's several collections of this period: The Lost Valley and Other Stories (1910), Ten Minute Stories (1914), and others. The book concludes with Blackwood's provocative introduction to a 1942 edition of John Silence.

The volume has been edited by S. T. Joshi, a leading authority on weird fiction who has established the most accurate text of Blackwood's tales.