Cats?
"Ngh- Sher?"
"Ah, you're awake."
"Wh-...Cats?"
"Cats, John."
"...How many?"
"Four."
"...And why are they in my bed?"
"Likely because it's the warmest space in the flat."
"...Why are they in the flat?"
"You can't expect me to leave them to the cold."
"...How long will they be here?"
"Only so long as the cold snap holds London in its cruel embrace."
"Right...My bed had better not be infested with fleas."
"Nonsense, it's far too cold for fleas now."
"They're likely not housetrained, Sherlock."
"It's a trivial thing to housetrain a cat."
"It really depends on the cat, as far as I know."
"Bah."
"...And what about Mrs. Hudson?"
"What about her?"
"Is she aware of her four new lodgers?"
"Temporary. Only so long as the cold snap lasts."
"It could be weeks, Sherlock."
"Perhaps."
"And why aren't they in your bed?"
"It's hardly warm, I'm never in it."
"Sherlock I can't even find space in my own bed."
"Nonsense, make your space and they'll find theirs."
"Ugh."
In a few months he'll need to find space amongst four cats and, after some developments, a clingy consulting detective. It truly is the warmest space in the flat.