Their situation was dire. It appeared they all would die by fire. Then Moriarty received a call, and slithered back to the place from whence he had come. Sherlock and John were spared to live another day. When Sherlock was home again, he fell upon his bed, wondering how and why they had escaped.
Moriarty filled his thoughts, but Sherlock made a decision. "My life is mine to choose," he said, "and so is my death. I will decide how I will go. I will not be ruled by fate."
Death was ever near now, always ready to take him, and he wondered which it would be: The snake, the crocodile, or the dog. He didn't understand how the dog could end his life, that is until Moriarty returned. They stood on the roof of Bart's hospital as he explained that John would die, if Sherlock didn't take his own life.
So Sherlock fell to his death leaving his friend behind. He fell, and all believed him dead, but he was not. He had disguised himself so that he could swim secretly through the seas of crime, searching for those who had plotted against them, and revealing all of Moriarty's crocodile tricks.
John knew none of this. He stood quietly crying beside the grave where he thought that Sherlock was buried.
