Could you please tell me what are the grammar mistakes in this discourse?

I am going to write a continuation of the story "The Wash-Tub" by W. S. Maugham. It tells the story of Mrs. Barnaby, a charming person and excellent story-teller who has an ability to make people eat out of her hand. In order to become a celebrity respected among the social elites she tells them fascinating made-up stories about her husband. Due to the fact that the old friends of the husband of Mrs. Barnaby (Mr. Barnaby) could easily prove the stories to be made-up he needs to stay in the shadow – far away from his wife. The narrator meets him in Positiano where Mr. Barnaby currently stays and accidentally gets to know about his secret.
In the continuation of the story I shall develop the plot of the relationship between the narrator and Mr. Barnaby. The situations they will face in the continuation of the story will change their relationship from strangers to close friends.

"The Wash-Tub" - continuation of the story

Having spent a few more days in Positiano I had decided to come back to Capri. The last night of my stay was unforgettable – Mr. Barnaby and I felt utterly at ease with each other. We got along very well which I found very surprising as we knew each other just for a little while. I felt like we knew each other for years. We admired beautiful Italian landscaped of Tyrrhenian Sea, olive valleys and long, rocky beaches. Before I left Positiano we had agreeably decided that we must arrange a meeting as soon as it would be possible.
Not more than 2 weeks later I received a letter from Mr. Barnaby in which he asked whether he could come to visit me in Capri. It was a very short letter beggining with words: "Positiano turned out to be boring without a companion to drink a bottle of wine with". "Well, is there anything else to do there?" - I smiled. At first I found it an excellent idea and I was just about to write a letter of invitation. However, after a short while I recalled a conversation I heard the day before in the restaurant. Three gossips sitting next to me were talking about Mrs. Barnaby who was apparently planning to visit Capri very soon. Certainly, I could not let them meet each other as it would ruin the lie they were building together for the last few months. It was very improbable there would be someone with Mrs. Barnaby who could recognize Mr. Barnaby. Nevertheless, I thought it was better to be safe than sorry. So, I sent Mr. Barnaby a long letter in which I gently explained the reasons for which he should not come to Capri for a next two or three weeks.
A loud knocking on the door woke me up the next morning. When I opened the door I saw smiling Mr. Barnaby with a small suitcase, dressed in a funny yellow suit with a pink bow-tie. "What a beautiful morning, isn't it?" - he said. "Indeed." - I answered. I was so glad to see him that just a few minutes later I easily forgot to mention what I had written in the letter Mr. Barnaby did not read.
We spent a charming evening eating delicious Italian food, talking, drinking wine and admiring the clear sky over the city of Capri. After a few bottles of Barbaresco we decided to see the huge Poseidon monument located in the centre of the old-town. It turned out to be far more majestic than we had imagined – perhaps it was the Italian wine that made it look even more beautiful. We were just about to continue our stroll when Mr. Barnaby accidentally run into a stranger and fell on the ground. A very tall Italian man gave him a look of disapproval, turned around and walked away with a woman who looked at him with nothing but disgust. I grabbed his hand to help him get up but he didn't move. "What's the matter?" - I asked. "It was her." - he answered. His face didn't express a single emotion. He just sat on the ground and watched them walk away.
Mr. Barnaby left Capri the very next day and I haven't seen him since that time. Two days ago I got a letter from him – it turned out Mrs. Barnaby decided to divorce him. She found his actions irresponsible as he could destroy their common dream of her becoming the best-known celebrity in Europe. "Can you believe this?" - Mr. Barnaby wrote - "She calls it 'our common dream'