I need someone to correct this short story for me. Thanks

The passage was pitch black and I was afraid to explore it on my own. So, I got out of the cupboard and went to tell my cousin Matthew about the secret passage. We decided to walk through the passage and see where it led. We dashed furtively into our grandma’s bedroom and took two torches from her bedside table. In the meantime, she was hanging the wash on the clothes line in the garden. We both agreed not to tell her anything because she would not approve our plan.
We tiptoed quietly to the cupboard, got into the cupboard and then we entered the passage. We flicked on our torches and when our eyes adjusted to dim light, we could see a long narrow passage. At the end of the passage, we could see a sturdy wooden door. The walls were low and dark. There were some cobwebs dangling from the ceiling but lucky me there were no rats. I can’t stand the sight of those ugly pests. We walked hurriedly through the passage and in no time, we were in front of the door. The door was locked with a rusty padlock but thankfully the key was in the padlock. Matthew turned the key slowly to make sure not to break the key in the padlock.
I could feel and see his excitement. He could hardly contain his excitement. His hand was trembling like a leaf and a layer of sweat broke out on his forehead and upper lip. Furthermore, it was hot and the air was musty. After two or three clicks, Matthew managed to open the door. The door creaked while I swung opened the door. The door led to a small chamber. There were a few old dusty cardboard boxes. This was not what we expected to find. We hoped to find a large treasure chest full of golden coins, precious stones and jewels. But it seems that this kind of stuff only happens in movies.
We decided to open some boxes. The opened boxes contained old fashioned clothes, torn books and some ornaments which had no value whatsoever. We were down in the dumps. To make matters worse we heard some footsteps approaching. We peeped into the passage and from her gait we realised that trouble was around the corner. Grandma has just found out what we have done!
We froze to the spot because we didn’t know what excuse we could bring up to get out of trouble. When she entered the chamber, she looked more afraid than angry. She was worried that we might get hurt. We were waiting for her to rebuke us but luckily, she only gave us a verbal warning.