Mycroft was in the hospital. Myocardial infarction the doctor had told John. Sherlock heard but didn't listen. His brother was deathly pale, dressed in a blue hospital gown, tubes going every which way to keep him alive.
John knew recovery would be hard for Mycroft; he loved sweets, and rich foods. He never exercised, but had stuck with the diet he had taken up when infiltrating a terrorist organization in Sweden when he was much younger, and fitter. John read his chart, and took everything in. Anthea came into the room, holding a stack of papers for Sherlock to sign. John hadn't noticed that Sherlock had pulled up a chair, and was holding his brother's hand tightly, scanning his body, looking for proof that it was something else.
Poisoning, possibly long term, red phosphorous, in hus morning coffee. But Anthea was smart enough to know Mycroft had successors, and that if she did she would be found out. Anthea stood beside Sherlock a few moments, patiently waiting for him to acknowledge her, but finally sighed, turning to John, leaving the papers beside the bed, and reaching over to draw the blinds. She took John's hand and pulled him out of the room.
Sherlock sat still, holding the cold hand of his brother. He leaned in, and whispered "I'm sorry, dearest brother."