Roylott’s room. In it were only three things. A camp bed. A wooden chair. And a large iron safe with a lamp on it.

Holmes tapped the safe. “What is in here?” he asked.

“My stepfather’s papers,” replied Helen Stoner.

“Are you sure there isn’t a cat in that safe?” asked Holmes. “Look at this!” He picked up a small dish of milk.

“We don’t keep a cat,” said Miss Stoner. “Just the cheetah and the baboon.”

“This milk would not go far with a cheetah,” said Holmes. “And what’s this?” He held up a small dog leash. The end of it had been tied in a loop.

I have never seen my friend’s face so dark. We went outside. We walked up and down the yard several times. Then Holmes spoke to Miss Stoner.

“You must do exactly as I tell you,” he said. “It could mean your life.” She nodded.

“See that inn across the street?” asked Holmes. “We will go there now. We will watch the house from there. Tonight I want you to go to bed in your sister’s room. Just as you did last night. Then wait until you hear Dr. Roylott go to bed. At that moment open and close the window. It will be a signal to Dr. Watson and me. Then go to your own room and wait.

“Watson and I will be waiting for your signal. Then we will leave the inn. We are going to spend the night in Julia’s room.”

“I think you already know what happened, Mr. Holmes,” said Helen Stoner. “Please tell me. How did my sister die?”

“We are not sure yet,” said Holmes. “We must leave you now, Miss Stoner.