Four years before, when Holmes "died," he chose to exercise his new freedom by traveling to places around the world where he had never been but which he had always had some interest in. One of his favorite countries, as he told me when he returned in 1894, was Nepal, but Nepal could never be entirely separated from India in his mind, and he had spent some months in India. While there, he was able to give two friends named Crewe and Carrisford the benefit of his assistance on a case which included proving Carrisford to be the true heir of a small fortune and personally guaranteeing the ownership of certain diamond mines. It is a complicated tale and one which it took him long to tell me, but the full tale of it involves certain personages who must not, at present, be named, and so I am barred from setting it all down here. Perhaps I may tell it in the future. At present, let it suffice to say that Holmes found himself more personally tangled up in the mystery than he was used to and was pleased to put it behind him and strike out for Nepal.
Two years later he returned to England and to his old life, refreshed and ready once again to pursue his own particular London criminals. It was less than a year following when, as he and I prepared to wrap up a case together (my dear wife Mary has never asked me to give up my associations with Holmes' work, much as I know it worries her at times; I love her all the more for it and curtail the more dangerous activities for her sake and the children's), a telegram came for Holmes. He tore it open hastily and, scanning it, went white to the lips. After a moment he dashed back into the house and began rummaging wildly in his bedroom. I found him cramming clothes into a carpetbag.
"Holmes, whatever are you doing?"
"I must return to India. I will take passage on the India Star, which is this evening leaving for Bombay. I don't know when I will be back. Not many months, I hope."
"Holmes, what is this? What is going on?"
He was still white as he stopped to stare at me. "I have made a grievous error, and at least one person has already paid for it with his life. I have no time or inclination to explain further. Do not ask."
I knew when it was futile to oppose him, so I did not ask, but I pressed him, "Holmes, what about the case?"
"What case?"
"The case we are on! The affair of the harpoon!"
"Oh, that. Nothing so simple, Watson. I have advertised in the newspapers for a harpooner. When the applicants come, you must have Lestrade arrest the murderer. Goodbye, Watson."
He wrung my hand and was away, despite my slightly despairing cry after him. I did not understand his instructions in the slightest. However, putting my head together with Lestrade's, we were able to fulfill them and did indeed end up capturing the murderer. It was quite obvious, when one looked at things the right way. Holmes, meanwhile, returned to India and came back five months later as I have described, a wreck.
The telegram had been from the young man named Tom Carrisford. He had sunk all his new fortune into diamond mines in India, on Holmes' recommendation, and persuaded his friend Captain Crewe to do so as well. The two young men turned out to be terrible business managers and between them and certain unscrupulous characters managed to lose the diamond mines and their fortunes into the bargain. Carrisford, suffering terribly from the brain fever that was then sweeping as a virus (as we now know it) through their small community and believing he was to blame for it all, fled in delirium, while his friend Crewe died raving. Coming slightly to his senses, Carrisford was able to send the telegram to Holmes, begging him to come and help him. Not only did he wish to regain his fortune and his honour, but he was desperate to find and help the small daughter of his friend Crewe. His actions, he believed, had wiped out Crewe's fortune and left the child destitute, without relations or place to live, and he did not know where she was. He had thought to find out her location from papers among his friend's things, but when he returned, he found a fire had destroyed everything. With no thought of blaming Holmes for his misfortunes, he turned to him as the only person who could help find her.
Holmes, for his part, never an emotional man, is a logical one, and logic told him instantly how he had set in place the train of events that led to Crewe's death and his child's destitution. How many times have I told him since then that he cannot possibly blame himself for others' actions? Carrisford and Crewe did not have to put their fortunes into the mines, or trust certain people. But even I can see the logic that brings it back to Holmes' door, and for a man who has spent his whole life protecting innocent people, the idea that he has, by extension, caused the death of one and the destitution of another is a devastating one.
It was almost too late when he made it to Bombay. He found young Carrisford in the final stages of his illness, almost too far gone to be useful. The horribly ironic thing was that the diamond mines had made a reappearance, thanks to the finding of some documents Carrisford thought he had lost or had been stolen. With his last strength, he made a will leaving everything to his friend's daughter and making Holmes executor. Carrisford died the next day, leaving a deeply shaken Holmes to take up the search for little Sara Crewe.
To begin with, he did not even know how old she was or whether she was still in India. He had managed to glean from Carrisford that she was in school, but it could have been school in the healthful Himalayan mountains or school back in England. Crewe himself had been a man beset with misfortunes that prevented the normal channels Holmes might have followed: his documents had been destroyed by fire; most of his regiment had been slaughtered in what was originally a small border skirmish with a stubborn maharajah; and the brain fever virus had decimated the community of English people who might know where a British Army captain had sent his daughter to be educated. After months of searching in India, with the slow fever moving into his own brain, he at last found someone who told him that the child's dead mother had been French and that Captain Crewe had probably sent her to school in France. Only then would he allow Ram Dass, Carrisford's servant who had steadfastly refused to leave Holmes' side after his sahib's death, to bring him back to England. He nearly died on the voyage over.
Author's note: I know next to nothing about viral meningitis, one of the possible explanations for Captain Crewe and Tom Carrisford's brain fever, so please forgive any inaccuracies.