"In a Glass Darkly" is a collection of five short stories in the horror and mystery genres, all presented as cases of a fictional physician whose researches lead him into the dark corners of the supernatural. The tales involve a range of eerie and macabre happenings such as a man being haunted by his doppelgänger, a cursed mirror, a deadly spectral wolf, a case of spontaneous combustion, and the iconic story of a woman being preyed upon by a female vampire. The stories are tied together by the posthumous papers of the occult detective Dr. Martin Hesselius.

The book is a chilling tale of psychological horror that delves into the fragile human psyche through the diary entries of a man who becomes increasingly convinced that he is not alone. He senses the presence of an invisible, malevolent entity that he calls "the Horla," which he believes is a superior being that has begun to exert control over his mind and body. As his paranoia and obsession with the Horla grow, so does his descent into madness, leading him to question the nature of reality, free will, and his own sanity. The story masterfully explores themes of existential dread and the fear of the unknown, culminating in a haunting and ambiguous conclusion.

This Gothic novella tells the haunting tale of a young woman's susceptibility to the charms of a mysterious female vampire named Carmilla. Set in a castle in Styria, the story unfolds as the protagonist becomes increasingly entranced by her enigmatic guest, whose true nature is gradually revealed through a series of eerie incidents. As the bond between the two deepens, a pattern of strange illnesses and deaths emerges, leading to the chilling discovery of Carmilla's vampiric identity and a desperate struggle to save the protagonist from a similar fate. The novella is a seminal work in vampire fiction, predating the more famous Dracula, and explores themes of sexuality, predation, and the supernatural.

This novel introduces readers to a world where ancient magic and modern day collide, centered around the life of Nicholas Flamel, a legendary alchemist who possesses the secret to eternal life. When his powerful book, the Codex, is stolen, Flamel and his wife must rely on the help of two teenage siblings, Sophie and Josh Newman, to recover it. The story unfolds across a backdrop of myth and history, weaving together a thrilling adventure that spans across continents and involves figures from lore and legend. As the twins discover their own untapped powers, they become central to the battle between the forces of good and evil, with the fate of the world hanging in the balance.

Set in a post-apocalyptic Paris, this novel weaves a tale of a city devastated by a war in Heaven, now ruled by fallen angels. The narrative centers around House Silverspires, once the most dominant of the magical houses, now struggling to maintain its power. Its inhabitants, including a newly fallen angel, a naive but powerful alchemist, and a mysterious human with a dangerous secret, must navigate the treacherous political landscape, unravel a sinister plot, and confront a malevolent force that threatens to destroy what little they have left. This story combines elements of fantasy, mystery, and Gothic horror to explore themes of power, loyalty, and redemption in a world where beauty and brutality coexist.