The Adventure of the Lion’s Mane :

The Adventure of the Lion’s Mane is one of Sherlock Holmes’s most unusual late-career cases—told entirely from Holmes’s own perspective after his retirement to the Sussex coast. When a local schoolmaster collapses on the beach, gasping the mysterious words “Lion’s Mane,” Holmes is drawn into a baffling investigation with no clear suspect, no human culprit, and clues that defy ordinary logic. As Holmes analyzes strange wounds, missing timelines, and the secret lives of seaside residents, he uncovers a deadly natural phenomenon as dangerous as any human adversary. Atmospheric, sharply observed, and rich with coastal tension, this story reveals Holmes’s brilliant deductive power in a rare solo narrative that showcases his mind at its most introspective and precise. Perfect for fans of classic mystery, detective fiction, and the legendary world of Sherlock Holmes.