Contrary to popular belief, Sherlock has a heart. It's in there somewhere. Very small, yes, very well-hidden, yes. Trained to stay in the back seat and be quiet and punished for every transgression, yes. But it is there. I know this because I have seen it. In glimpses, flashing like single frames of film, I, John Watson, have borne witness to this fact. It exists.

Mrs Hudson, for instance. He'd rather die than admit but one word from her… She says jump, and Sherlock mumbles darkly, covering up his willingness, "And just how high would you like that to be, then?"

Or, as in this case, she says, "It's those bloody foxes again," and here we are sitting in a pair of squeaky, shaking deck chairs in a foot of snow.

I was going to be content. I was going to be calm, and stoic, and quiet. But with the edge of my thumb nail I have just tested and I can no longer feel the tips of my fingers, so there's that all gone for a burton. "What do think you're going to do?" I ask him. "Oh, God, please don't tell me you've got a gun."

"Don't be ridiculous, John."

"Then what?"

"Reconnaissance. Once I understand their movements, their behaviours, I'll be able to formulate an effective plan of attack and capture." And I was the one being ridiculous. The really terrifying thing is that he doesn't even know how that sounds. That is honestly his plan. I think I'm staring. He tells me I do that sometimes. "John, you have that face on. The one that makes you look like a baffled dog. You don't seem to understand, the first weapon in any war is knowledge of the enemy."

…You have to love when he tells me about war.

"Well," I say, standing up, "Good luck with that." He says nothing as I pass him. But his eyes follow me. When I look round, though, they flash away, looking instead at my empty chair. He's shivering. Pity gets the better of me. "Last call for a cup of tea." Sherlock mutters something about keeping a clear head. "Well, I'll bring you out a blanket then."

"I'm fine as I am."

Well, if he's going to be a child about it… I stay to see him ball up his fists, burying them under his arms, just long enough for him to change his mind. I bite back the urge to tell him not to come crying to me when he develops hypothermia over a couple of Mrs Hudson's bloody foxes.

Guilty? No, why should I be guilty? If that's how he's choosing to spend a winter night, good on him. Who am I to get in his way?

No, absolutely without guilt, I go back inside, upstairs, make tea for myself and myself alone, and park myself in front of the news. Not something I get to do very often. Sherlock doesn't like the news. He's always saying it's wrong without explaining why, so I don't even try to watch it anymore. Once I got him to stop throwing jam at the morning paper when it displeased him it wasn't a problem anymore.

Still. Hello, Kirsty Wark. Been a while. What're you up to these days, aside from Newsnight? Hang in there; Paxman's all washed up. Another couple of years, you'll be running that program.

But Kirsty comes and goes. Program ends. And I get to the bottom of that tea.

So I get up, make another two cups, throw a blanket round my shoulders and go back out there.

Sherlock takes the mug out of my hand when I offer it. Takes one end of the blanket when I throw the other across my knees. "What changed your mind?"

"Nothing on telly. Any sign of Basil Brush yet?"

"Who?"

"What sort of childhood did you have? The fox, Sherlock."

"No sign yet. And there won't be if you don't lower your voice." Oh, fine, then… I settle back in my seat and try to remember what brought me back out here. Certainly not pity again. I offered him that and he turned it down. And certainly not guilt, because I never felt that to begin with. Stupidity, probably. Denseness. All the things he's ever accused me of and I've gotten all offended about it? All true, every one of them, apparently, and here I am.

Sherlock, maybe just afraid of losing my company again, sits back too after a while. Softly, almost drowned out by the sound of deck chair wobbling in the snow, "What's Basil Brush?"

"Posh fox, green stalking jacket, 'boom-boom'?" I look at him until he looks back. Answering a question I haven't asked yet, he shakes his head. "Kids' TV. It's had a reboot lately."

"…It's a fox? In a hunting jacket and 'boom-boom' is the catchphrase?"

"I think that was supposed to be the joke."

"Is that a message they put on children's shows?"

This has the potential to be a very long night. On the other hand, if Basil Brush can leave him so perplexed, what would happen if I tried to explain The Smurfs, or The Moomins? There's potential, here, for a bit of fun. And I think I'm owed a bit of fun right now, don't you?

"Sherlock, let me tell you a story about the magical Singing Ringing Tree…"

Eight hours and twelve half-remembered programs later, when dawn is rosy over Baker Street and not a single coppery brush has appeared all night, I stop to yawn. Sherlock snivels and stands up, spine crackling back into a better position. "Well, that's one mystery solved," he mutters.

"What? The foxes? But there weren't any."

"Not the foxes, John. No, this country. I no longer wonder why it is we belong to a generation of overeating, alcoholic, psychologically unstable wrecks."

I follow him inside with the blankets and the mugs. The deck chairs are staying where they are. That scares me a little. That implies the deck chairs are going to be used again. Not sure how I feel about that. As we stumble numbly into the kitchen, "You're blaming television? Very original."

Mrs Hudson's already up. She's got fresh tea on, and bacon frying. Sherlock asks, "Are you sure it was foxes you heard before? There was nothing. And we were still and quiet enough not to have disturbed them, so there ought to have been."

"Oh, they wouldn't have been out last night, boys," she trills, that little laugh (almost, in fact, as though we're being ridiculous), "The bins were emptied yesterday. There's nothing for them yet."

Sherlock, as I said, has a heart and, as I said, especially when it comes to Mrs Hudson. But then, a long night in the cold quietly suffering an entire childhood's worth of disturbing fiction will wither away most good and true things in a man. I don't stop him when he charges out of the room. And it nothing more nor less than the smell of the bacon that keeps me from following suit.