The morning light splintered weakly through the frost-clad windows of 221B Baker Street, outlining the specks of dust suspended in the chilled air. Sherlock Holmes sat hunched in his chair, his dressing gown loose around his wiry frame, the ends of his violin bow trembling against taut strings. The melody was not one of beauty but of calculation. each note piercing, searching, weighing an unseen truth.

"Holmes," Watson interjected, his own hands steadying a cup of tea that had long since cooled, "Inspector Lestrade is waiting downstairs. He insists it is urgent."

Holmes didn't look up, but the corner of his mouth curled faintly, as if he already knew the gravity of the matter. "He will wait. Tea leaves steep no faster under duress."

"Good God, man," Watson grumbled, setting his cup down with more force than intended, "there's been a death."

"There always is," Holmes said softly, his bow descending in a long, deliberate stroke. "Fetch your revolver, Watson. I suspect this particular corpse will demand its own peculiar justice."

The body lay sprawled in the center of an otherwise orderly room at the Royal British Museum, its hands twisted as if clawing at unseen threads. A man of perhaps fifty, his thin spectacles hung askew on a face frozen in an expression of profound dread. Around him, nothing was disturbed save a lone inkpot toppled from the desk. The ink had bled across the victim's notes, rendering his last calculations indecipherable.

Lestrade shifted uneasily beside Holmes. "Name's Dr. Bernard Whitby. Mathematician of some renown, though I doubt that interests you. Found this morning by a janitor, locked in from the inside."

"Locks," Holmes murmured, crouching low over the corpse, his sharp eyes darting across every wrinkle and shadow. "How quaintly they deceive."

Lestrade blinked. "Deceive?"

Holmes ignored him. He reached for the ink-stained papers, holding them delicately at an angle beneath the light. "The ink spreads in predictable patterns, yet here, an anomaly. This blot suggests the inkpot was not merely knocked over."

Watson, standing stiffly behind him, cleared his throat. "Are you implying the inkpot was deliberately spilt after his death?"

Holmes straightened abruptly, his gaze now on the faint scuff marks near the chair. "Not after. During."

Lestrade crossed his arms. "The door was locked. There's no sign of entry or exit. What could anyone have done during, let alone after?"

Holmes's hands hovered over the body's chest, careful not to touch. "The heart races when fear takes hold, Lestrade. The dying man reached for salvation not out of logic but instinct." He pointed to the man's splayed hands. "Do you see the indentations on his palms? Circular, deliberate. He held something as he died. And not his pen, it's untouched."

Watson leaned in. "What sort of object?"

Holmes smiled without warmth. "That is precisely the question, my dear Watson. What sort of object is worth dying for?"

The museum's curator, a stern woman in her sixties with a gaze sharper than her spectacles, stood at a respectful distance as Holmes prowled the mathematician's private study. He trailed his fingers just above the surfaces of bookshelves, desks, and cabinets as though feeling vibrations invisible to lesser minds.

"This room is sterile," he muttered. "Too sterile. Our man feared contamination."

The curator frowned. "Dr. Whitby often claimed his calculations were of utmost sensitivity. He distrusted all but himself."

"And yet," Holmes said, pausing before a small glass case that gleamed faintly in the lamplight, "he allowed this." Inside the case lay an ornate key, its surface marred with faint scratches, as if it had been handled too often and too roughly.

Watson peered closer. "A key? To what?"

Holmes's voice was quieter now, more deliberate. "To knowledge best left unopened. The question, Watson, is not what the key unlocks but who deemed it necessary to lock it in the first place."