Horror has always promised the same thing: you walk into the dark, confront a monster, and walk out again. The creature dies. The credits roll. You go back to work. They Only Come Out at Night: A Hidden History of Horror follows that ritual across 200 years and asks a different question: who built these monsters, under what conditions, and what work are they really doing? It moves from Gothic serials to streaming queues, but stays close to the films themselves. Frankenstein appears not just as a myth about a scientist and his creation, but as a story assembled out of industrial anxiety, stolen labour and copyright theft; Mary Shelley's original and the Universal version sit side by side and are pulled apart. Dracula shows up as both a tale of aristocratic predation and a legal mess that left Bram Stoker's estate cut out of cinema history. The early Universal hits are treated as factory products: contract actors, studio backlots, costume departments and makeup chairs turning Karloff and Lugosi into icons while keeping them precarious and replaceable. From there, it runs through Psycho and the collapse of the Production Code; Night of the Living Dead and a finale that looks less like "order restored" than a class army sweeping the countryside clean-race absolutely present, but folded into a wider structure of state and property violence; The Texas Chain Saw Massacre and a shoot that nearly broke its crew; slashers that turned economic dread into masked killers; video nasties passed hand-to-hand and seized by police; and the home-video boom that made small films globally visible while funnelling most of the money elsewhere. Prestige festival hits and so-called "elevated horror" sit next to franchises and streaming originals. The Exorcist and the Conjuring series are read as religious instruction welded to genre spectacle. Get Out is placed in a long line of films that talk about race while leaving class and capitalism largely untouched. The Babadook, Hereditary, Midsommar and other recent touchstones are treated as arguments about grief, gender, family and power, always in relation to the business that financed them and the audiences they're allowed to reach. International horror runs right through the story, not as exotic colour but as work being mined: J-horror's technological ghosts, Korean films and series that cut closer to class than most Hollywood releases, Spanish, Thai, Indonesian and Turkish films that drag local traumas into view before being flattened into "content" for global libraries. The final chapters step into the present: YouTube narrators staring at analytics at 2 AM, Netflix commissioning and cancelling horror off numbers creators never see, TikTok and short-form platforms pushing horror toward clipped shocks, and the rise of AI tools that promise monsters, scripts and even voices that can be generated without human workers at all. At every stage, They Only Come Out at Night comes back to the same core: horror doesn't just mirror our fears, it helps manage them. Economic precarity, war, empire, unpaid care, climate breakdown, algorithmic dependency-terrors rooted in how society is organised-are stripped of their causes and turned into single bodies that can be stabbed, burned, exorcised or exploded on cue. The monster dies so the system doesn't have to. Behind that argument sits a full documentary spine: hundreds of films and series, production histories, trade papers, censorship records and interviews, all tracked in detailed endnotes. It's written in plain language, but it treats horror-and the people who make it-with the seriousness of real history. If you love horror, it will change how you see the work you already know by heart. If you think you hate horror, it might explain why the world keeps needing it.