It was half-past five before Holmes returned. He was bright, eager, and in excellent spirits,—a mood which in his case alternated with fits of the blackest depression.

“There is no great mystery in this matter,” he said, taking the cup of tea which I had poured out for him. “The facts appear to admit of only one explanation.”

“What! you have solved it already?”

“Well, that would be too much to say. I have discovered a suggestive fact, that is all. It is, however, very suggestive. The details are still to be added. I have just found, on consulting the back files of the Times, that Major Sholto, of Upper Norword, late of the 34th Bombay Infantry, died upon the 28th of April, 1882.”

“I may be very obtuse, Holmes, but I fail to see what this suggests.”

“No? You surprise me. Look at it in this way, then. Captain Morstan disappears. The only person in London whom he could have visited is Major Sholto. Major Sholto denies having heard that he was in London. Four years later Sholto dies. Within a week of his death Captain Morstan’s daughter receives a valuable present, which is repeated from year to year, and now culminates in a letter which describes her as a wronged woman. What wrong can it refer to except this deprivation of her father? And why should the presents begin immediately after Sholto’s death, unless it is that Sholto’s heir knows something of the mystery and desires to make compensation? Have you any alternative theory which will meet the facts?”

“But what a strange compensation! And how strangely made! Why, too, should he write a letter now, rather than six years ago? Again, the letter speaks of giving her justice. What justice can she have? It is too much to suppose that her father is still alive. There is no other injustice in her case that you know of.”

“There are difficulties; there are certainly difficulties,” said Sherlock Holmes, pensively. “But our expedition of to-night will solve them all. Ah, here is a four-wheeler, and Miss Morstan is inside. Are you all ready? Then we had better go down, for it is a little past the hour.”

I picked up my hat and my heaviest stick, but I observed that Holmes took his revolver from his drawer and slipped it into his pocket. It was clear that he thought that our night’s work might be a serious one.

Miss Morstan was muffled in a dark cloak, and her sensitive face was composed, but pale. She must have been more than woman if she did not feel some uneasiness at the strange enterprise upon which we were embarking, yet her self-control was perfect, and she readily answered the few additional questions which Sherlock Holmes put to her.