A loud whizzing sound filled the air, followed by the sharp tinkle of breaking glass. In that instant, Holmes leaped out of the shadows and tackled the marksman, forcing him face-first onto the floor. The man, showing surprising strength, quickly pushed himself up and grabbed Holmes by the throat.

Acting fast, I moved behind him and struck his head with the handle of my revolver. He collapsed back onto the floor. I held him down with all my strength, using my arms and knees to pin him in place while Holmes blew hard on his whistle, calling for help.

There was the sound of running feet, and three men rushed into the room. Two were policemen in uniform, and the third was a plain-clothed detective. I realized he was the man I had seen earlier standing in the doorway.

"Is that you, Lestrade?" Holmes asked.

"Yes, Mr. Holmes. It's good to see you back in London, sir."

"I thought you could use some help. Three unsolved murders in one year isn't very good, Lestrade."

The two policemen took over holding the prisoner, who had gotten back on his feet.

In the light of their lanterns, I saw the prisoner clearly for the first time. He had a weathered face, like someone who had spent years outdoors. His blue eyes were sharp and strong, but also cold, like a hunter. He ignored everyone except Holmes, staring at him with a mix of hatred and surprise. "You devil," he kept saying. "You clever, clever devil."

"My dear Colonel," Holmes replied, "I don't think we've met since the day you threw rocks at me above the Reichenbach Falls. Gentlemen, let me introduce Colonel Sebastian Moran, formerly of Her Majesty's Indian Army, and the best big game hunter in the East. No one has hunted more tigers than you, right, Colonel?"

The old man glared at Holmes. With his fierce eyes and bristling moustache, he looked a little like a tiger himself.

“I’m surprised my simple plan tricked an old hunter like you, Colonel,” said Holmes. “Have you ever tied a young goat under a tree and waited with your rifle for a tiger to come? This empty house is my tree, and you are my tiger.”

Colonel Moran lunged forward in anger, but the policemen held him back. His face was filled with rage, and it was frightening to see.

“I admit you surprised me in one way,” Holmes continued. “I didn’t expect you to use this empty house and shoot through its front window. I thought you’d attack from the street, where Lestrade and his officers were waiting for you. Other than that, everything went as I planned.”

Colonel Moran turned to Lestrade. “Do I really have to listen to this nonsense? If I’m under arrest, why not take me to the police station?”

“That sounds fair,” said Lestrade. “Holmes, is there anything else before we leave?”

Holmes had picked up the air gun from the floor and was looking closely at it.

“This is an amazing weapon,” he said. “It’s silent but very powerful. I believe it was made by a German engineer for Professor Moriarty. I’ve known about this gun for years, but this is the first time I’ve seen it. Lestrade, you should study this gun and the bullets it uses.”

“We’ll do that, Mr. Holmes,” said Lestrade. “Anything else?”

“No, no, Lestrade. Please don’t mention my name in this case. There’s a much bigger crime you can connect this man to.”

“What crime is that, Mr. Holmes?”

“The murder of Ronald Adair.”

“You mean this man killed Adair?”

Holmes nodded. “Yes, Lestrade. With your usual bravery and cleverness, you’ve caught the man who committed the crime that shocked all of London. Colonel Sebastian Moran shot Ronald Adair with an expanding bullet from this gun. He shot him through the open window of a second-floor room at No. 427 Park Lane on the 30th of last month. That’s the charge, Lestrade.

“And now, Watson, if you don’t mind the cold from the broken window, shall we go back to my study across the street? I have a story that I think will entertain you.”

Our old home looked much the same as it did three years ago, but it was much tidier. After Moriarty’s gang set fire to the place, Mrs. Hudson and I decided to redecorate it in the same style. Holmes was especially happy to see his old acid-stained table and violin, which had survived the fire with only a little damage.

Mrs. Hudson was very relieved to see we were safe after our adventure. “I adjusted the wax dummy just like you told me, sir,” she said, pointing to the wax figure of Holmes on a small table near the window.

“You did an excellent job, Mrs. Hudson,” said Holmes. “Did you see where the bullet went?”

“Yes, sir. I’m afraid it damaged your beautiful sculpture. The bullet went right through the head and into the wall behind. I picked up the bullet from the carpet. Here it is.”

Holmes looked at it. “It’s a revolver bullet,” he said. “It’s clever because no one would expect a revolver bullet to come from an air gun.” He examined the bust’s forehead. “The old hunter was a great shot. He was the best in India and probably in London, too.”

Mrs. Hudson left, and we sat in our familiar armchairs by the fire, which flickered in the breeze coming through the broken window.

“Have you heard of Colonel Moran, Watson?”

“No, I haven’t.”

Holmes took a book from his shelf and said, “Here we are. It’s my ‘A to Z of Famous Criminals.’” He sat back in his chair and started flipping through the pages. “I have a great collection of criminals listed under M. Besides Moriarty, there’s Morgan the poisoner, Meridew the forger, and Mathews, who knocked out my left tooth at Charing Cross. And finally, there’s the man of the hour...”

He handed the book to me, and I read the entry about Colonel Sebastian Moran.

He was born in London, the son of a rich politician. He went to Eton and Oxford and served bravely in the British Indian Army. “This is surprising,” I said, giving the book back. “He came from a wealthy family, had a great education, and was a brave soldier. What went wrong with him?”

Holmes replied, “Some trees grow well but then develop a twisted shape. The same can happen to people. Colonel Moran was a good person for much of his life, at least on the surface. But for some reason, he started to go wrong.

“He retired from the army, moved back to London, and turned to crime. Soon, he caught Moriarty’s attention and became his right-hand man. Do you remember when I visited you in April 1890 and insisted on closing the shutters because I was afraid of air guns? You might have thought I was being paranoid, but I knew Moran was out there with his dangerous gun.

Holmes explained, “The reason I spent so much time traveling was because of Moran. As long as he was free in London, I couldn’t come back. I was always at risk from his gun, and eventually, he would have had a chance to attack me.

“While I was in France, I kept track of London news, waiting for the right moment to get rid of this threat. My chance came when Ronald Adair was killed. Everything I knew about Moran suggested he was the murderer. He had played cards with Adair, so he must have followed him home and shot him through the open window. The type of bullet used proves his guilt.

“I came back to London quickly and made sure Parker, Moran’s watchman, saw me. I knew Parker would tell Moran I was back, and Moran would realize that I had figured out he killed Adair. He would try to act fast before I could talk to the police. I set up a good target in the window and warned the police they might be needed.

“I thought the empty house would be a safe place for us to watch for his capture. I never expected he would choose that same house for his attack. Now, Watson, is there anything else you need to understand?”

“Yes,” I said. “But you haven’t explained why Colonel Moran wanted to kill Ronald Adair.”

Holmes replied, “We can only guess about Moran’s reason. Your guess might be as good as mine.”

“You have a guess then?” I asked.

“Yes,” Holmes said. “We know that Moran and Adair often played cards together and had won a lot of money. I also know that Moran cheats at cards. Adair might have found out and threatened to expose him. If Adair did that, Moran would have been ruined because he relied on cheating at cards for money. That’s why Moran killed Adair.”

“And why did Adair lock his door?” I asked.

“He was trying to figure out how much money he should return because he didn’t want to benefit from cheating. He locked the door to keep anyone from seeing the names and cash on his desk and questioning him.”

Holmes smiled and put another log on the fire. He looked as happy as I was to be back in our old home. “Does my theory seem reasonable, Watson?”

“I’m sure you’ve found the truth,” I replied.

“Well, we’ll see at the trial. For now, Colonel Moran will bother us no more. His famous air gun will be put in a museum. And Mr. Sherlock Holmes is free again to enjoy solving the interesting little problems that make life in London so enjoyable.”