Back inside 221b John went to his room and sat on the edge of his bed. He ran his hands though his hair, got up and went to look out of his window. Nothing seemed different. He sat back on the bed and asked himself what he had expected to see. He couldn't answer, so he took off his shoes, placing them next to his bed, lined next to each other and facing out. Habits from the army he couldn't break. Standing up, he smoothed out the creases from where he had sat and walked into the living room.
Sherlock was lying on the floor face upwards, hands clasped together on his stomach. Apart from his odd choice of place to lie he looked peaceful. His eyes snapped open when John shuffled in. Still lying on the floor he looked John toe to head but said nothing. John sat on the sofa and sighed.
"Why are you on the floor?" he asked in a way that suggested the question pained him slightly to say it. Sherlock tilted his head towards john.
"Storing and remembering" he answered nonchalantly.
"On the floor?"
"The brain stores and recalls information better in strange environments. So by lying down here I can store more detail than usual."
John didn't think two of those things could be possible; the first being that Sherlock could store more information than normal. The second being that a possible detail from today's events could ever be forgotten.
"Sherlock, you're the most rational man I know-"
"Thank you" Sherlock responded before John had finished his sentence.
"I'm not sure it's a compliment Sherlock. Sometimes you put rationality before other people's feelings". He trailed off. Sherlock had closed his eyes again and cocked his shoulder slightly to show he wasn't listening anymore and didn't care either. John began to speak again and Sherlock snapped his eyes open, rolling them dramatically.
"Anyway, you saw the same as me. But it's just not possible. I know Lestrade told us not to go there but I never thought..."
Sherlock sat up, leaning on his hands that he placed behind him.
"Listen to me John. We have both been duped. What that was, back there. Not possible. Illogical, inconceivable and absurd. Just forget about it."
"But back at the building you believed it too. I heard you say 'it can't be'. That means you believed it too doesn't it?" John asked anxiously.
"No John. I have thought it all through and there are many different explanations for what we saw."
John was losing his temper now.
"SHERLOCK. I SAW IT, YOU SAW IT! It was a... zombie." He said the last word quietly as if one could walk in at any moment.
Sherlock snorted at the ridiculous word.
"John, the undead are not roaming the streets of London, or shuffling around a deserted building for that matter. Don't use that word either. You sound like Anderson."
Anger and fear bubbled inside John, closing his eyes he began to relive the day's events...