Based on the flashback scene in chapter 59
Life and death were not meant to meet. They were only to dance around each other, never to be in an embrace, never to touch; only to watch from afar and complete the story written. When the story does not go as planned, what are life and death to do but fall in love?
The fall hurt, every bone, every ligament, every muscle groaned in pain. Sherlock could barely even move. A weight dragged him down, something in his arms. This weight was not unwelcome, nor was burdening. It was comfortable, soft yet scary. His one true friend was held in his embrace as they broke the surface of the water.
He could see nothing, the world was dark and his head was pressed against Sherlock's chest. He could feel nothing but the warm embrace of his so-called rival. He could hear nothing but the water surrounding them, the gasping breaths, the slow heartbeat. It was terrifying, but those arms were still wrapped around him as the water consumed them. Sherlock never let go.
It felt like Sherlock gasped for breath as he woke up, his body sore and breath ragged. He looked around the room, terrified and saw his Liam asleep on a bed across from him. Sherlock went to stand up, as he did so his legs gave out, sending him falling back on the bed. "At least we survived Liam. We'll see this new world together," A slight smile rested upon Sherlock's face as he looked over to the unconscious man, "we're here together, Liam."
Sherlock met the boy named Billy who took care of them as they drifted on the ocean, following the currents to America. The boy was kind and helped Sherlock tend to Liam's wounds. He'd tell Sherlock stories, and they'd play games but Sherlock still sulked, still longed for Liam to come to.
He was a root jutting out of a river, the water and the world around him changed as he was stuck, never moving. William was stuck in limbo, he couldn't move, he couldn't feel anything, but he could hear, his mind was active though his body was not. It was like an elongated sleep paralysis but his eyes could not open, they were locked doors with no key. His ears were the only part that worked, that collected information, useful information.
He heard a young boy from America talk to Sherly, the boy's name was Billy. Would they always adopt children with the name of Bill? They were apparently on a ship, heading towards America. A new land, a new life. William was unsure of what was to come, he was terrified but Mr. Holmes- Sherlock would be with him so it would be okay. This would be okay. Liam kept telling himself that he wanted to believe it, to believe that this new opportunity would be better that he deserved this; but his mind was tired, and his fears, his pain only grew. No matter how many times Sherlock would sit at the side of the bed saying "I love you, Liam," no matter how many times Sherlock caressed his face, he still believed he didn't deserve this. He didn't deserve Sherlock's kind words, he didn't deserve to be saved. He couldn't atone for his sins by living, his life didn't mean anything unless it was gone. That was his plan, that's what he believed.
Some days, when his mind grew tired and he began to slip back into unconsciousness, William wished he wouldn't wake up. He didn't want to deal with his thoughts, or feelings. He didn't want to battle the pain in his chest. He wanted his plan to be carried through, that was easier than handling his pain.
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Sherlock sat beside the bed, for the umpteenth time this week. He grabbed Liam's hand, as softly as he could. He never wanted to disturb him, even if he was in a coma. He never wanted to hurt him, and seeing Liam like this was terrifying. He never stirred or spoke, no movements or sign of life other than his breathing, but even that felt too subtle. He wanted something more, so he'd know without a doubt that Liam was alive. He didn't want to lose him, not like this. His hand was placed softly on top of Liam's and he moved his thumb to caress Liam's hand, the caress was soft as soft and slow as a raindrop cascading on a window.