I left out the following sentences. Thank you.

1) In particular, he decides to gather a thousand friends in his castle. After five or six months of their stay there, he decides to hold a masked ball, which will take place in seven rooms.
2) The rooms are all set in a way that one cannot see from one room to another; besides, they all are in different colours but each room the colour of the glass of the Gothic window is the same as the colour of the ornaments.
3) Only the last one is all black with a red window. All the guests are enjoying themselves and dancing. However, when a clock with a pendulum strikes the hours, the orchestra stops playing and the people stop dancing, as if they were all frozen.
4) They all resume their activities as soon as the clock finishes chiming. When the clock strikes midnight a man, with a red costume covered in blood and a mask on his face that makes it look like the face of a dead man.
5) He moves to and fro with solemn movements. When Prince Prospero tries to stop him, he immediately dies. The same happens to his friends who try to touch him but realize there is no tangible form under the costume.
6) One by one all the people in the castle die and darkness falls all over the place.

1. Remove "there" - or rephrase: After five or six months there...

2. I'm not clear on what you mean by this: "but each room the colour of the glass of the Gothic window is the same as the colour of the ornaments." Are some words missing? Or are there too many words (redundancy?)?

3. OK

4. Comma needed after "midnight" and not needed after "man" - wordiness: "a mask on his face that makes it look like the face of a dead man."

5. Clarify who the "his" and "him" are. Red Death? Prospero?

6. Comma after second "one" and after "die."

1) The passage describes a story where a character decides to gather a thousand friends in his castle for several months. Eventually, he plans to host a masked ball in seven different rooms.

To find this information, you can refer to the original source material or read a summary or analysis of the story. Look for a comprehensive summary of the story or search for specific keywords like "masked ball," "thousand friends in castle," or "seven rooms."

2) The rooms in the castle are designed in a way that they cannot be seen from one room to another. Each room has a different color, and the color of the glass in the Gothic window matches the color of the ornaments in that room.

To understand this aspect of the story, pay attention to the descriptions provided in the original source material. Look for descriptions of the rooms, their colors, and any mention of the Gothic windows and ornaments.

3) During the masked ball, all the guests are enjoying themselves and dancing. However, when a clock with a pendulum strikes the hours, the orchestra stops playing, and the people freeze as if time has stopped.

To grasp this part of the story, refer to the original text and look for the scene where the clock strikes the hours and causes the people to freeze. Take note of any descriptions of the guests' reactions and how their actions are affected by the clock striking.

4) When the clock strikes midnight, a man in a red costume covered in blood and wearing a mask that resembles a dead man's face appears. He moves solemnly, and when the prince tries to stop him, the man immediately dies. The same fate befalls anyone who tries to touch him, as they realize there is no physical form under the costume.

To understand this sequence, read the relevant part in the story where the man with the red costume appears. Look for descriptions of the man's appearance, the prince's reaction, and the outcome when someone tries to touch him.

5) One by one, all the people in the castle gradually die, and darkness falls over the place.

To grasp how all the people in the castle meet their demise, read the passages leading up to this event. Look for descriptions of their deaths and the resulting darkness that envelops the castle.

If the original source material is a book or a short story, reading the entire work will provide a better context and understanding of the events described in these sentences.