The flesh in the furnace by Dean Koontz

The excerpts present a bleak science-fiction narrative focusing on Pertos Godelhausser, a puppeteer who tours with his mentally challenged assistant, Sebastian, and a machine called the Furnace that creates and recycles lifelike, sentient puppets. The central conflict arises from the puppets’ existential horror at being constantly murdered and reborn, leading them to despise Pertos, their creator. After Sebastian violently kills both a patron and Pertos himself, the simple-minded man becomes the puppets' new, clumsy "god," wielding the power of the Furnace and carrying Pertos’s mind-altering Holistian Pearl. The lead puppet, Bitty Belina, soon exploits Sebastian's deep-seated fears and guilt to force him to resurrect her full company of vengeful comrades. Having gained their full complement and secured their liberation by destroying the Furnace, the puppets capture Sebastian and sadistically crucify him, cementing their role as a new, murderous evolutionary force.