The best mystery I've read is"Why the Dr. Went Mad" because it really is a mystery and it isn't solved, even at the end of the story. I doubt the author even knew the end to the mystery! Here's the beginning of the mystery I'm writing for L.A. It's called .
"The Legend of the Hunt"
Charlotte Hunt looked up from her watchful post over her brand-new baby girl, Helen. She’d been hearing the same noises for the past hour. It sounded like multiple heavy footsteps grinding across the floor, and they were getting louder by the minute. Helen gurgled happily from her bedside crib. Charlotte rested her gaze on her, but snapped her head back up when she heard heavy breathing outside the door. She leapt to her feet.
“Damien, is that you?” she called out to her husband.
There was a pause. Then there was a deafening noise of cracking wood as the door was knocked down. There, in the doorway, stood a gigantic metal beast with clawed feet. Charlotte gasped as she saw it held in one clawed hand a giant, shinning silver sword, tipped with black poison. She recognized the sword at once. It was the worst nightmare of the Hunt family. Charlotte was overcome with emotion as she looked upon the sword that had killed her mother, and her grandmother before that. Now this creature would surely kill her with the same weapon that had pierced all of the Hunt women.
Charlotte backed up against the wall, paralyzed with fear. The beast advanced and with a slice of his sword, she lay on the ground, holding her bleeding stomach. Charlotte heard the back door being unlocked, but her brain was in too much of a fog from pain that she didn’t hear the groceries hit the floor and her husband come rushing to her side.
“Charlotte!” he said, surveying her bleeding body.
“Damien...Watch out! It’s the Hunt!” With these words the beast came and took the bloody sword in both hands and sliced her head off with one clean swipe.
Not even the sound of the outside world could have blocked the screams of sorrow and hatred from Damien as the beast quietly turned and walked away.