It is a cold and miserable afternoon, even by a teddy bear's standards. The fog has descended over the three storey house which I call home and everyone is huddled into the living room. Mycroft's nose is buried in a book, Mummy's eyes are drooping as she tries to watch the news on television and Sherlock is being kept entertained by arranging his toys into order by size (apparently I'm not included in his row of toys so I must assume that I'm supposed to be helping him). Indeed, once he's placed his plastic lion key fob and ring at the smaller end, he gets to his feet and stands back.

He grins triumphantly at his effort but it soon descends into a frown. There is light snoring coming from Mummy now and I am pleased to hear it: she needs a rest. Sherlock is still frowning. "Hmm…" he mumbles his newfound word and what he now says when he's thinking. Then another relatively new word: "Bored." He picks me up by the paw and takes us away from the living room. I notice Mycroft's eyes flick from his book to us for just a moment before my vision is obscured by a door.

Sherlock does four laps of the house before an idea seems to pop into his head and he makes his way to the kitchen. It's a Sunday so I'm surprised to find the kitchen devoid of Cook. Sherlock doesn't seem to share in my surprise. He sets me down on a kitchen chair so I can observe and says, with a finger to his lips, "Shh, Teddy."

He toddles over to a low cupboard. He opens it to reveal sauces in bottles. He shakes his head to himself and moves on to the next. This one has pots and pans neatly stacked, and again he shakes his head and closes the door. He keeps going in this fashion all the way around the room before he finally finds what he must have been looking for. He comes back into view grinning and holding a paint can up for me to see. Oh, no…

If there is one thing a teddy bear hates more than rain or mud, it is paint. It sticks everywhere and clogs fur and it's really difficult to remove. Not that I wish to ruin his fun, but I would prefer that he put the paint back. I try to tell him so, but he's already picked me up and we're in the dining room before I can blink. The can swings by Sherlock's side as he walks and I notice to my horror that the lid is loose – Sherlock is going to have no problem opening it.

He sits down just beside the grand and probably ancient and undoubtedly valuable dining room table. He has me on one side and the can of paint on the other. He reaches for the can and easily takes the lid off. Paint comes away on his hand, a bright yellow, and he sets the lid down on the floor and I know that there will be a ring of paint left behind when it is lifted again.

Sherlock gets to his feet and stands over the paint can before dipping his hand into it. He runs around the dining table with his hand to the floor and he leaves a trail behind him. Then he spots a bare spot on the wall and carries the can over (thankfully he leaves me where I am) and dips his hand into the paint again, giving the liquid a good mix.

Then he starts to draw on the wall. The walls are cream in colour so the yellow is hardly striking, but that's not what I'm worrying about right now. With smooth movements of his right hand he soon has what looks like the ripples of the ocean on the wall. He dips his hand again before moving on to the boat and sails. He adds a few seagulls and a stick man to the boat and stands back to admire his handiwork.

We hear footsteps approach and Sherlock turns and runs, picking me up with his yellow hand as he passes. As I feared, the paint clogs my fur and makes his hand stick to my tummy. He slips through the door and into the kitchen. Here he pauses momentarily, scanning for a decent exit. He chooses the kitchen door that leads to the garden. There are running footsteps behind us now and so Sherlock breaks into the fastest run that he can manage.

My day gets a whole lot worse as we run along the garden path before ducking behind a thick tree. It is cold out here in the garden, wet and muddy, and Sherlock sets me down beside him. He places his yellow palm over my muzzle and leans close. "Mycroft's following us – we have to be quiet," he whispers into my ear.

We hear the kitchen door open and close, then running on wet grass. Sherlock is about to get up and find us a better place to hide but before he can a hand lands on his shoulder. He looks up to see Mycroft looking down at him, shaking his head. I would have expected shouting, anger, rage, but Mycroft simply leads Sherlock by the clean hand into the house and I am taken in Mycroft's other hand.

Somehow the silence, the expressionless face, is even scarier.

Once we are back in the warm kitchen, Sherlock's big brother sets him down on a chair and holds me up for Sherlock to see. From my new perspective I can see the mud on Sherlock's trousers and the drying paint on his hands and face, his red ears and nose from the cold. Mycroft says, like a confession or a secret, "This bear, Teddy… means a lot to me. I want you to promise me that you'll look after him, OK?"

Sherlock doesn't make eye contact but nods, "OK."

"Promise me."

"I promise."

"Good. Now go and find Nanny and get her to clean you up," instructs Mycroft. "I'll try to clean the mess you made in the dining room before Mummy wakes up."

He sniffs, but Sherlock does as he's told and skulks off, his gaze firmly on the floor.

Once his attention-seeking little brother is out of sight, Mycroft gives me an inspection. Paint around my middle, on my nose and on one of my paws, plus the added bonus of mud on my legs. He takes me into a small and narrow room and puts me into some sort of shiny metal box with a round door. He tuts and closes the door before pushing a few buttons.

The world begins to spin.

As the world spins I lose track of time. I see a blurred figure through the distorted glass joined soon after by another. The figures are watching me and it's only when the spinning stops that I realise who the figures are: Sherlock and Mycroft, both watching with poorly concealed worried faces.