Spots 
Claiborne Coe returns to the rotting mountain town of Creston after seven years in the Orient, intent on marrying Valyne Kirk with his hard-earned money. Instead of a warm reunion, he finds an empty street and a cryptic letter from his adopted father, Dr. Latham Kyle. The letter explicitly forbids the marriage, claiming an inherent stain and sinister venom flows within Claiborne's blood.
Part 1
Hostile villagers shrink from Claiborne Coe as he walks through Creston toward Dr. Latham Kyle's house. Learning that Valyne Kirk moved there after her mother's death, he looks up at Blue Squaw Mountain with resurfacing childhood terror. Years ago, Claiborne discovered a hidden stone altar and felt an inexplicable urge to bleed upon it, prompting Dr. Kyle to demand a lifelong vow of silence.
Part 2
Valyne Kirk flees through the mountain timber, pursued by Jud Geer, a giant butcher stained with blood and driven by brutal lust. Claiborne Coe intervenes to protect her, but receiving a blow triggers a terrifying psychological shift. A violent rage overwhelms Claiborne's rational mind, releasing a blind, destructive frenzy he has feared since childhood.
Part 3
Claiborne Coe comes to his senses to find Jud Geer bloodied on the ground with crushed lips and broken teeth. Reminded of a lethal fight in Singapore, Claiborne revolts at his own capacity for extreme violence. Jud sullenly checks a large ticking watch before staggering off into the gloom, leaving Valyne to bandage Claiborne's bleeding knuckles.
Part 4
Sensing a corruptive atmosphere hanging over Creston, Claiborne Coe urges Valyne Kirk to hire a car and flee immediately. Valyne refuses to leave tonight, revealing she promised Dr. Latham Kyle they would converse before marrying. They walk hand in hand to the doctor's gray stone house, whose sinister windows and gloomy aura fill them both with heavy foreboding.
Part 5
Old Sarah Kyle greets the couple under ancient ceiling beams, cackling with strange warnings about walking too near hell. She reveals that Dr. Latham Kyle is in his attic study completing a manuscript on Creston's local demonolatry. Upstairs, Claiborne Coe meets the servants, mute Eben Hand and his domineering wife Josepha, who observe him with unsettling scrutiny.
Part 6
Eben Hand silently signals interest upon hearing of Claiborne Coe's foreign earnings, fixating on his gold ring. At the staircase, Dr. Latham Kyle appears, his head shriveled to the likeness of a bare yellow skull. The doctor grimly insists that Claiborne's inherent corruption will drag Valyne Kirk into a living nightmare if they go through with their marriage.
Part 7
During supper, a distress signal from silent Eben Hand prompts Dr. Latham Kyle to rush toward the cellar door. A agonizing scream of animal agony echoes from below, yet Sarah Kyle continues eating calmly while asking about Claiborne Coe's tin and copper mining in Szechwan. Returning to his seat, Dr. Kyle whispers that something below grows restless because Jud Geer is late.
Part 8
Jud Geer arrives with a bandaged face and a milk can filled with fresh blood to deliver to the cellar. His glazed eyes fixate on Valyne Kirk with explicit lust before Dr. Latham Kyle pays him and sends him away, leaving a dark red ring on the floorboards. Moments later, Eben Hand frantically signals that the subterranean creature refuses the blood because it senses Claiborne Coe's presence.
Part 9
The inhabitants of the house stare at Claiborne Coe in horror as feral whining echoes from the cellar floor. Dr. Latham Kyle privately pleads with Claiborne to relinquish Valyne Kirk and depart forever without demanding the true secret of his heritage. Before Claiborne can refuse, violent crashing, snapping chains, and splintering wood signify that the locked cellar beast is breaking free.
Part 10
Dr. Latham Kyle and Sarah Kyle rush downstairs to control the escaping entity while Claiborne Coe confronts Valyne Kirk. She tearfully admits her fear, yet embraces Claiborne tightly, reaffirming her unconditional love regardless of his lineage. Dr. Kyle reemerges shaken and urgent, begging Claiborne to follow him down to the cellar to avert an immediate catastrophe.
Part 11
Descending into the cellar, Claiborne Coe encounters a heavy masonry wall featuring a small barred window and an overpowering, acrid animal odor. Prompted by Dr. Latham Kyle to speak, Claiborne recites poetry, drawing a monstrous, noseless creature with burning red eyes to the iron gate. Hearing Claiborne's voice, the horror calms down, purrs like a cat, and begins lapping the blood.
Part 12
In his attic study filled with demonology texts and occult idols, Dr. Latham Kyle unveils Claiborne Coe's ancestral lineage. He explains that the Coe family line dates back to Salem witchcraft, practicing continuous dark arts across generations. Claiborne's grandfather, Eliakim Coe, reached the apex of this sorcery and ultimately sacrificed his own daughter, Elizabeth, in a sinister ritual.
Part 13
Dr. Latham Kyle details how Elizabeth was bound across the mountain altar where a cosmic dark entity claimed her, resulting in the birth of twins. Claiborne Coe carries this dark blood in a recessive state, explaining his lifelong feelings of alienation and his unmanageable violent rages. Dr. Kyle warns that yielding to romantic passion will ignite this blood, transforming Claiborne into a monster.
Part 14
Dr. Latham Kyle reveals that the beast chained in the cellar is Claiborne Coe's twin brother, raised secretly in a mountain cave by their mother for twenty years. Upon her death, Dr. Kyle harbored the creature to serve as proof for his book on local sorcery. He warns Claiborne that marrying Valyne Kirk will pass this monstrous heritage directly to any offspring they produce.
Part 15
Overwhelmed by the conviction that his blood is fundamentally corrupted, Claiborne Coe retreats to his room and decides suicide is his only recourse. Hearing distant howling and clanking chains from below, he cocks his .45 automatic pistol and presses the barrel to his temple. Before he can pull the trigger, Valyne Kirk bursts through the doorway and forcefully pulls his arm away.
Part 16
Valyne Kirk refuses to abandon Claiborne Coe, declaring her love remains unshaken even if the doctor's claims are true. Inspired by her devotion, Claiborne holsters his weapon and promises to live and flee Creston with her the following morning. Their resolve is immediately shattered when old Sarah Kyle enters the room to announce that the cellar beast has broken its chains and vanished.
Part 17
Sarah Kyle warns that the monster previously exhibited intense predatory obsession toward Valyne Kirk after seeing her through the cellar bars. She instructs Valyne to lock herself inside her bedchamber while the household searches the premises. Sarah alerts Claiborne Coe that his twin will either seek him out due to shared blood or target Valyne in a fit of violent jealousy.
Part 18
Claiborne Coe inspects the ruined cellar cell, noting the torn iron door and an intense acrid scent that allows him to track the beast. Rushing up to Valyne Kirk's locked room, he breaks inside only to find an empty bed and a smashed window overlooking the shed. Sarah Kyle confirms the monster climbed the roof, shattered the pane, and carried Valyne off into the dark mountain wilderness.
Part 19
Sarah Kyle insists that Claiborne Coe's shared blood will lead him directly to the ancient stone altar on Blue Squaw Mountain. Driven by desperate impulse, Claiborne navigates the dark, thorny woods until he reaches the moonlit glade surrounded by towering monoliths. Inside the circle, twin fires flank the black altar, where Valyne Kirk lies bound beneath a gigantic, horned, hooved monster.
Part 20
Overcome by destructive fury, Claiborne Coe charges the monstrous creature, engaging in brutal hand-to-hand combat against its immense strength and cloven hooves. When his sanity clears, the beast lies motionless near the altar, bleeding from a fatal bullet wound in its skull. Claiborne unties the shivering Valyne, wraps his coat around her, and resolves to walk into the timber to end his own life.
Part 21
Dr. Latham Kyle steps into the firelight holding a smoking rifle, admitting he shot the creature to save Claiborne Coe. Claiborne announces his intention to commit suicide in the forest, which the doctor coldly encourages as a necessary act to prevent monstrous offspring. As Claiborne turns to walk into the shadows, Valyne Kirk regains consciousness and desperately screams that the entire situation is a calculated hoax.
Part 22
Valyne Kirk identifies the ticking of a cheap watch, prompting Claiborne Coe to inspect the corpse and pull off a painted rubber mask. Beneath lies the face of Jud Geer, exposing the monster as a total fabrication. Trapped, Dr. Latham Kyle coldly admits to constructing the entire hoax to drive Claiborne to suicide, aiming to inherit the fortune Claiborne brought back from the Orient.
Part 23
Dr. Latham Kyle reveals that Claiborne Coe's grandfather was merely an unhinged murderer rather than a sorcerer. The doctor raises his rifle to execute Claiborne and Valyne Kirk, planning to stage the scene as a fatal rivalry between Claiborne and Jud Geer. Before he can pull the trigger, Claiborne's subconscious combat reflexes draw his hidden .45 automatic, killing Dr. Kyle and allowing the lovers to escape Creston forever.
Part 24
A return home uncovers an elaborate Gothic plot designed to exploit fear and steal a fortune.