Next morning Holmes was up early and had disappeared somewhere, but was back for breakfast.
"Good morning, Holmes," said Sir Henry. "You look like a general who is planning a battle."
"That's just so. Watson is waiting for orders."
"And so am I."
"Very good. I understand that you're invited to dine with your friends the Stapletons tonight."
"I hope you'll come too. They are very nice people."
"I fear that Watson and I must go to London."
"Yes, I think we'll be more useful there at present."
Sir Henry's face lengthened. "I hoped you would stay with me. It isn't very pleasant to be alone at the Hall and on the moor."
"My dear friend, you must trust me and do what I tell you. We'll return very soon. Please tell your friends that we have very important business in town and cannot visit them tonight."
"All right, if you insist on it. When do you wish to go?"
"Immediately after breakfast. Watson, please send a note to Mr Stapleton to tell him you cannot come."
"I think I'll go with you to London," said Sir Henry. "Why must I stay here alone?"
"Because you gave me your word to do exactly as I asked you. You must drive to Merripit House this evening, but you'll walk home across the moor."
"Across the moor? That's just what you told me never to do."
"Yes, but tonight you may do it safely. Remember, you must walk straight along the path which leads from Merripit House to the Grimpen road. Don't ask me the reason. Everything will be all right."
"I've promised to obey you and I'll do just what you say," answered Sir Henry.
An hour later Holmes and I were at the station at Coombe Tracey. A small boy was waiting for us upon the platform.
"Ah, Cartwright, so you found my note in the hut this morning. Now, take the train to town. As soon as you arrive you'll send the following telegram from me to Sir Henry Baskerville: 'If you find pocket-book dropped by me, send by post Baker Street, Holmes.' Do you understand?"
"Good. Now, Watson, let's visit Mrs Laura Lyons."
Holmes's plan was clear. He would not go to London, but the Stapletons must think he had gone. Sir Henry would tell them about the telegram and they would believe him.
Mrs Lyons was at home and Sherlock Holmes told her at once that he had come to speak to her about the death of Sir Charles.
"Dr Watson says you haven't told him everything."
"What have I not told him?" she asked angrily.
"You said that you had asked Sir Charles to be at the gate at ten o'clock. We know that that was the place and the hour of his death, but you know more, I'm sure."
"I know nothing more," she answered.
"Mrs Lyons, I must tell you that we suspect murder and we think that Stapleton and his wife -"
At these words she sprang from her chair. "His wife!" she repeated again and again, "his wife! If you can prove it I'll tell you everything."
"I've come to do so," said Holmes, taking several papers from his pocket. "This is a photograph of the two of them, taken in York four years ago. It's signed 'Mr and Mrs Vandeleur,' but you will easily recognize them. Here are some documents proving that Mr Vandeleur was a school teacher in York. The photo was taken there."
She glanced at the photograph and the papers, then looked at us. There was despair in her eyes.
"This man has offered me marriage on condition I should get a divorce from my husband. He has lied to me. He has been deceiving me all the time. I was only a tool in his hands. Ask me what you like and I'll tell you everything. Only believe me, when I wrote that letter I didn't think it could harm the old man who had been my kindest friend."
"I believe you, Mrs Lyons," Holmes said. "Don't tell me anything. I'll tell you what happened, and you can correct me if I make a mistake. Stapleton told you to write that letter to Sir Charles."
"He dictated it."
"He told you," Holmes continued, "that Sir Charles would give you money."
"Yes," she said.
"And then, after you had sent the letter, Stapleton told you not to go to the gate."
"He told me he would get the money himself."
"And then he made you swear to say nothing about the appointment with Sir Charles."
"Yes, he frightened me by saying that the death of the old gentleman was very mysterious and that I would be suspected if it became known that I had asked him to come to the gate. I loved Stapleton," she added, "and believed him. Now I understand what a criminal he is."
We left Mrs Lyons and returned to the station to meet Lestrade — the official police officer whom Holmes had called from London by telegram early that morning. The nets were closing on Stapleton.