Sherlock was taking a rare trip on the Tube, the Jubilee Line to be exact, when he spotted his brother for the first time that day. The man was stood on the opposite platform at Westminster station, perfectly still and resting on his umbrella. Sherlock blinked but Mycroft was gone.
Thinking nothing of it, Sherlock continued his day. He rushed around London on his latest case, trying to ignore the feeling of being watched. It felt like Mycroft was always in his peripheral vision, but he knew that couldn't be true. His brother hated legwork and wouldn't spend a whole day following him around the rainy city.
It was midnight when Sherlock arrived back at 221B. He trudged up the stairs and flicked on the living room light. He paused, seeing his brother sat in John's armchair. It was definitely Mycroft but he looked younger.
"I had a feeling you'd be here. Did you enjoy following me around London?" Sherlock said sarcastically, sitting down opposite his brother. He couldn't help but stare at his brother. This was the Mycroft who'd just graduated Oxford. His skin was full of life and his ginger hair shone. He was 21 and he was exactly as Sherlock remembered.
"I wanted to see you. One last time." Mycroft replied; even his voice sounded younger.
"Have MI6 developed a potion to make you younger?" Sherlock asked, half-jokingly.
"I'm going away for a while, but I'll still be in the memories in your mind palace." Mycroft said.
Sherlock watched his brother as a memory appeared in his head, "That's what you said to me before you left for university." he realized. Sitting opposite him was 21 year-old Mycroft, repeating the words of 18 year-old Mycroft. He frowned, thinking that he had to be dreaming.
"Goodbye Sherlock. The world is your oyster." Mycroft continued, getting up and walking away.
"No, Mycroft, wait!" Sherlock called, going out into the hallway. He froze. It was empty. There was no Mycroft. He looked around in confusion before he pulled his phone out from his pocket. It began to ring as he held it.
"Sherlock Holmes." he answered.
"Sherlock...it's Anthea...it's about Mycroft..." Anthea spoke gently, "He's dead..."
Sherlock ended the call immediately. He had nothing to say. He went back inside the living room and sat down, looking at the empty armchair opposite him. Mycroft was dead, what was there to say?
He let Anthea organize the funeral but he didn't attend. He didn't want to see the cold stone with Mycroft's name engraved on it. That stone wasn't his brother so what was the point in seeing it? He threw himself into cases, determined to work through his grief.
The silence that Mycroft left behind was almost unbearable. Now his brother was gone, he was alone. John and Anthea did their best to provide support, but it was Mycroft's relentless interfering that he missed the most. He knew he should feel free, with Mycroft's eyes no longer on him, but instead he felt trapped. Who would be there to protect him now his big brother was gone?
It wasn't until he was an old man, sat alone in the garden with his bees, that he allowed himself to remember the strange visit from his brother. He didn't believe in the supernatural, but Mycroft had been there to say goodbye - he was sure of it.
"Stop frowning, little brother. You'll get wrinkles." Mycroft said from beside him.
"Mycroft." Sherlock murmured with a weak smile. It was a nice feeling to see his brother again, so many years after Mycroft's sudden death.
"Come along, Sherlock. Let's play deductions." Mycroft said, smiling and offering his hand out.
Sherlock Holmes took his brother's hand with a smile. He was found dead by his carer just one hour later, sheltered from the rain by a black umbrella with a wooden handle.