Sherlock was gone.
John had searched the flat, every room, every nook and cranny, even the roof, but Sherlock wasn't there.
Sherlock had remained silent all evening, not eating the scarce canned rations they had rescued from neighbouring houses, not even making a snide remark when John tried suggesting going to live with Mycroft. But when he had gone to bed without a word, John had imagined he would still be there in the morning.
Horrible thoughts raced through his head... Zombies bandits Moriarty what if what if what if... But there was one option he tried to block out, tried not to think about, it was too horrible, but now it was all he could think about.
Suicide.
Images of that day raced through his mind at light speed. The day he had thought Sherlock was gone forever, never coming back. Yet Sherlock had once again tricked his way out of what to normal people would be certain death. But this time, maybe he wouldn't fight it. Maybe he wouldn't come back.
John felt sick. Lights danced before his eyes. He was dizzy, hyperventilating, his mouth was dry. He tried to clear his panicked head. Where would he go if he was going to kill himself?
The answer was obvious. The same place he had gone three years ago. St Bart's.
Before he knew it, his coat was on and he was running to St Bart's. He rounded the last corner, faster than any of the times he'd been pursued by zombies. There was a skinny, pale form stood on the roof of St Bart's, looking down at the ground.
"Sherlock!" John roared.
He flew through the doors, up the stairs three at a time. There was carnage all around him, although he barely processed it. The bodies of zombies lay still, blood pooling around them. The walls and floor were riddled with bullet holes. Windows were smashed, medical equipment was strewn over the floor.
But John's mind was elsewhere. He climbed the final set of stairs that led to the roof, and eventually stopped, panting, as he stood behind his best friend.
"Sherlock," he wheezed, "please, come over here."
"I killed her, John," Sherlock said quietly.
"What? You killed who, Sherlock?"
"Molly."
John was stunned. He searched for words, not sure whether he wanted to comfort or question the man. After what seemed like an age, he settled for, "Why?"
"She was infected. So, I... I put her down. I put her down, like a sick dog. Along with all the rest of her pack." Tears threatened to drip from his eyes.
"Don't be stupid, Sherlock. She wasn't Molly anymore. Molly was gone."
Sherlock eventually turned to face his friend. "She hadn't turned yet. She was still exactly the same as always. She was... she was scared. Scared that she was going to become a zombie, scared that I was going to kill her. She died scared."
John hung his head. "It had to be done," he whispered. "She was only going to kill people. You had to kill her before it was too late."
Sherlock took one final look at the pavement below, before tentatively walking towards John. "I need to get out of here, or else I won't be able to live with myself. We should... we should go to Mycroft."