The Tragedy of Otranto is a big spooky story where many very old and important people all try to take a BIG castle at the same time. It all starts when a powerful man named Manfred wants to make sure his family keeps control of the castle. He pokes around in a secret room and finds this strange old helmet with magical powers. When he picks it up, a huge gust of wind blasts through the room and knocks him down.
After that, very strange things start to happen. A giant helmet comes down from the sky and crushes one of the most important people in the whole castle to death. Then everyone starts to see ghosts, and hear weird sounds, and the castle starts to fall apart. Manfred and his family try to hold on to their power, but everything just keeps getting worse and worse.
In the end, nobody wins. Almost everyone dies, Manfred's family loses control of the castle, and it still isn't really clear what happened to the magical helmet. It's all very spooky and mysterious, and people still like to read and talk about it today!