John is not a cat person.
He's never been a cat person, which makes his life as Sherlock Holmes's flatmate / blogger / mother / let's-just-not-think-about-it even more absurd, because Sherlock lacks only the ability to pin his ears flat and a tail to actually be a cat, and John apparently likes him just fine. He tries not to think about it too hard.
Still, it’s not like John is a mean person or anything, so when the cat looks up at him from the doorstep, soaking wet and skinny as a rail, and opens its mouth in a silent demand for succor, John gives in. When he opens the door, the cat slinks in and up the stairs, as if it knows exactly where it’s going, and as John follows it he can see where the creature’s tail is dripping steadily onto the stairs.
It’s waiting for him by the flat door, and when John lets it in, it pauses for a minute, staring directly at Sherlock, before shooting under the couch at a speed that is the more astonishing for being performed in a wary crouch.
“Is it a client?” says Sherlock, from where for no reason John can tell, he is lying with the top of his head resting on the floor and the rest of his body supported by his chair. It looks terribly uncomfortable. John can only suppose it has something to do with a gruesome murder by torture and how long it would take for bloodflow to the head to make a victim lose consciousness.
Or Sherlock’s been at the sugar again, in which case John is turning right back out and hiding at Mrs Hudson’s.
“It’s a stray,” says John shortly, and goes to coax the cat out. He thinks that when the cat is dried and fed, it will look rather respectable. Mid-Victorian. He’ll probably be able to convince it to eat, and it will grow a belly and jowls.
Gladstone, he thinks.