**The Unrelenting Bargain**

The air hung heavy with tension as Elara steeled herself, her eyes locked on Zha'thik's piercing gaze. She knew she had to act quickly, to protect her students from the ancient being's wrath. With a deep breath, she spoke, her voice firm but laced with a hint of resignation. "I... I agree to serve you," Elara said, the words feeling like ash in her mouth. Zha'thik's response was immediate, its voice like a crack of thunder in the minds of those present. "Excellent choice, Professor. Your... compliance shall be rewarded." As if summoned by the entity's words, a gleaming, crystalline wardrobe materialized beside Elara, its surface etched with intricate, swirling patterns that seemed to shift and writhe like living serpents. The wardrobe's doors swung open, revealing a dazzling array of lingerie that seemed to shimmer and glow in the dim light of the classroom. Elara's eyes widened in horror as Zha'thik's voice whispered in her mind, "Don the red ensemble, Professor. The one with the delicate, lace-trimmed corset and the silk stockings. It will suit my tastes perfectly." With a sense of impending doom, Elara approached the wardrobe, her hands trembling as she reached for the specified lingerie. Her students watched in frozen silence, their faces pale with worry and fear, as she carefully selected the outfit. As Elara began to change, her clothes falling to the floor in a discarded heap, her students looked away, unable to bear the sight. When she emerged from the wardrobe, they couldn't help but gasp in shock. Elara stood before them, transformed into a vision of jaw-dropping beauty. The red corset hugged her curves, accentuating her figure in ways that seemed almost... provocative. The delicate lace trim and silk stockings added a touch of elegance, but it was the overall effect that left her students breathless. Elara's eyes, however, told a different story – a tale of fear, of resignation, and of a deep, abiding sorrow. Zha'thik's voice echoed in their minds once more, "Ah, Professor... you look exquisite. My desires are already... piqued." The entity's gaze seemed to burn with an inner fire, its gemstone-like eyes fixed on Elara with an unnerving intensity. The students knew that they had just witnessed the beginning of a terrible, Faustian bargain – one that would change their lives, and Elara's, forever.