It happened in the morning. It was about eight o'clock in the morning. A young strange looking lady visited my house. She was nervous and she needed to speak to me as soon as possible. I invited her to the living room and asked her sit and calm down. I had to wake up my co-worker Dr. Watson. He wasn't happy that I had woken him, but he put the clothes very quickly and went down the stairs.

When we got the living room, we asked the lady, why she had been so nervous. She answered us that she had been very afraid. She told us that her name was Miss Helen Stoner and she described us her situation. She told us about her stepfather. His name was Mr. Roylott and he was a doctor in India. He was quite rich and unfortunately hot-tempered and he managed to kill his servant. Then he was sent to prison and became the worse man than hew had been earlier. He came back to England. When he was in prison, Miss Stoner's mother died. She spent a lot of money to set Mr. Roylott free. His hobby was the Indian animals. He also possessed a baboon and a cheetah.

Miss Stoner told us also that her sister unfortunately died two years ago. She was only thirty years old. So then we were sure that her death was the reason of that visit. Then the lady added that her sister two couple days before her weeding. We asked her to tell us something about her sister. She started to describe her house and we were listening very carefully. There were three bedrooms (hers, Julia's one and the doctor's one). They were next to each other. Her sister's bedroom was in the middle. Then she told us about that terrified night. Dr. Roylott as usual was in his room and probably was smoking a cigar. The cigar's smoke came to Julia's bedroom, Julia decided to go to her sister room. They were happy and were chatting about her wedding. Suddenly, Miss Stoner heard someone's whistling. Miss Stoner added that Julia always was used to turn the door key, because she had been afraid of the Indian animals.

Then Miss Stoner went on. She became nervous. She remembered that night. She couldn't sleep. It was about three o'clock when she heard her sister's screaming. She heard the whistle again and the falling of the piece of metal. Without any thoughts she ran oust side her room and saw her sister standing before the doctor's door. Her sister was speckled band and she was pointed at his door. Then she died.

I decided to ask the lady some questions. She didn't know about the reasons of her sister's death. She though that the reason was the extreme fear. She added that the worse fact of that death was that she was going to get married. Couple weeks later Miss Stoner had to move to Julia's room, because of the repair in her own room. And that night she heard whistling again. As soon as the dusk came she left home and went to see me. 

After a few minute about her story I told her what we should do. At first, we should visit Miss Stoner's house. We arranged the meeting at that afternoon. We were talking about the details with Dr. Watson, when all of the sudden someone came in. It was a man wearing a hat. He told us that is name was Dr. Roylott. He added that he knew that Miss Stoner had visited us. He seemed to be very angry and he advised that not to put the nose into someone's businesses.

He left and we decided not to think about that incident. We started working. I really wanted to see the last will of Miss Stoner's mother. There was written that each daughter would receive 10000 pounds, when she decided to get married. The rest of money would receive Dr. Roylott. However, it wouldn't be a huge sum of money. When I came back, I told Dr. Watson about everything I had learnt. Then we went to Miss Stoner's house.

We saw her waiting for us in front of her house. We had to tell her about Dr. Roylott's visit. She showed us the whole house. I managed to guess which room supposed to belong to every member. I managed to check the shutters. When we entered the building, I decided to check Julia's room very carefully. I found out that the bell ring, which supposed to be new, didn't go anywhere. It was hanging and didn't work. I wanted to check the first floor. I noticed that the bed wasn't moveable. I decided not to tell about my notices. The next thing I realized it was a ventilator, which didn't go into any room. It wasn't the real ventilator. I thought it was a kind of suspect. I thought that it might be a kind of bridge between the hole and the bed.

Nest I went to Dr. Roylott's room. Inside there were a lot of furniture as well as a huge safe. Miss Stoner didn't have any what might be inside. I saw a small saucer on the safe and a kind of whip. I also noticed someone's footsteps at that chair. It seemed to be clear, that he probably used that chair to stand on it. He put an animal inside the ventilator hole. I thought that he put his snake into the ventilator hole. Soon I realized that that kind of whistling was the signal to snake to come back. Then we decided to leave the house as soon as possible to be not to seen by Dr. Roylott. When we left house, I had a plan. We arranged Miss Stoners would turn the light on, when doctor came back his room. We should also spend that night in Julia's room to check the whistle.

We went in the nearest building and observed Miss Stoner's house. At eight o'clock the light turned off. So we came to the house and waited in Julia's room in silence. I had been waiting for a long time and nothing happened. At four o'clock in the morning we saw a kind of light in the ventilator's hole. We heard that someone was moving quietly in the next room. For couple of minutes there was the silence. Then we heard the hissing. I knew what that was. We were staring at the hole and all of the sudden we heard someone's crying and screaming. I told my friend: "The story is going to repeat!". We went outside the room and quickly went to Dr. Roylott's room. Doctor was standing on the chair and keeping the whip in his hand. He was looking at the ventilator. We saw he was holding the snake. Doctor didn't even move, when we entered the room. But the snake became very nervous. The snake bit the man and soon Dr. Roylott died. He was biting by his own snake! I quickly took the whip and I managed to carry the animal inside the safe, where was his place. Miss Stoner saw the whole situation.

So I supposed to explain the situation to every one. Dr. Roylott wanted to kill Miss Stoner to get the whole sum of money that his wife directed to her daughters. When the snake filed to bite Miss Stoner, it came back through the ventilator's hole and bit the on it first saw. The snake was nervous and he bit Dr. Roylott. We saw the moment when the snake bit the murderer. Miss Stoner was safe!