Two days after asking for present, I wake up without Pa in Bed. I sit up to look for him and he is sat in Chair number two. He is staring strangely at the wall. He turns to look at me. I see a big box on Table. My present! Pa got me a present! I jump out of Bed so fast, I'm quicker than ever before. I reach Table and touch the box. I've never seen one so big! Pa tells me to open it, so I do but really slowly, because I want it to last. Pa and I say 'Appreciate what you have'. I must make present last forever. I pull sticky stuff off slowly and open the lid. I kneel on Chair number one so I can see inside. There are so many books, my eyes almost pop out of their sockets! I run to Pa and pull him over to the box so he can see better. We pull out ten books and some pencils and crayons. I can't read yet, so I ask him what the books say. Pa tells me that there's an encyclopedia for children and spelling books. There's also math and science and activities, but the best one is the big book. Pa says there are stories in it to last a whole year. Pa is so excited, he grabs my hands and we waltz as far as Chain will let us. We laugh and I hug Pa and I thank him for asking Them to get me presents. He goes very quiet and hugs me back. I think he is too happy to talk.

Pa makes me wait until after lunch before we can start school. He says he has to get ready to teach me, so he spends morning getting lessons ready. He writes with a pen, but Pa says he has trouble because he hasn't used one in a while. He uses a stick called a ruler and does some drawings on the paper that came in the box. I nag him until he gets cross and he tells me to practise hiding from monsters. I like this game. Pa shouts "Monsters!" and I have to run all the way to Wardrobe, all seven steps and I have to lock myself in until Pa says "Safe!". The monsters aren't real, just like pirates aren't real, but games are still my favourite things to do. Until lessons.

Time passes slow like a snail and I get cross with it. Pa gives me his watch and I stare at it. I play with Soft Ball. There are lots of seconds in a minute and even more in an hour. Pa says use time wisely, so I practice running around Room. After thirty circles I am tired and I lay on Bed to catch my breath. I hold it in my lungs until I almost burst. I make noises with my mouth until Pa says I'm driving him up the wall. I ask him which wall and he laughs. Then we have baked beans for lunch and Pa tells me he's ready.

"Right," says Sherlock, stretching, "Come here, young man. I'm going to walk you to school."

"But we're in Room, Pa."

"Yes, we are. But you see, from now on, Bed is home and Table is school," he takes Jack's hand, "are you ready?"

"Yep!"

"Here we go. Let's cross the road," they take two steps forward, "Now we turn right down this alley and we reach another road. We have to watch out for cars. Look left, look right and we cross. Through the park, can you see the squirrels in the trees? Look out!" They jump to one side.

"WHOOSH!"

"Phew! That boy on the skateboard was fast. Have to watch out for them. And now we're in school. Ready to learn?"

"Yes!"

"Brilliant," Sherlock watches Jack with a look of pride on his face. They share a smile, "Let's get learning."

While Sherlock knows that his son's attention span is impressive for his age, he also knows that he can't push his luck too far. After two hours of simple equations, learning to spell letters and reading, Sherlock calls it a day. They put everything away in the box and push it under Bed, mindful not to squash Eggsnake. Then an idea crosses Sherlock's mind and he pulls the box back out and scribbles 'Jack's school box' on the side. Jack stares at the way his name is spelt and files it away in his Mind Palace. He takes a piece of paper out and puts it in Wardrobe for later.

When he looks back at Pa, Sherlock is sat down on the edge of Bed, his eyelids drooping, even more tired than he usually is at this time of day.

Jack sighs. "Why are you always son tired, Pa? You sleep more than me."

Sherlock cracks one eye open and peers sleepily at his son. He appears to weigh up his options and considers the most appropriate answer he can give. Then he leans forward, resting his elbows on his knees, his chin resting on his finger tips and looking Jack in the eye.

"Do you remember what I told you about Chain?" he asks.

"Yes, you said Chain was your punishment for trying to leave Room, before I was born."

"That's right. I tried to leave Room because you weren't here yet and I was lonely and sad. I was-" he pauses as he gives his answer more thought. "I was jealous because Old Magnussen and the Witch could leave Room together and I… I wanted company. Sometimes I got very angry at Them and I tried to fight Them. Even with Chain I would fight Them. So one day, to help me, after you were born, they gave me tablets that I still have to take."

"Just like my vitamins. Except you swallow yours with water."

"A bit like vitamins, yes. But whereas yours keep you full of energy and healthy, mine make me tired and unable to fight back, or at least, not as much. Do you understand?"

Jack mulls over this new information, processing it and putting it on a shelf in his Mind Palace. "But you don't need to fight anymore, Pa, because you've got me. That way you won't have to take bad tablets anymore."

Sherlock stares at him sadly. "I have to, Jack. Let's just say Chain knows if I haven't and he'll get tighter. But that's not the problem."

"What is the problem?" asks Jack, innocently.

Sherlock presses his lips into a fine line, looking more upset than Jack had ever seen him. "It's not me I'm worried about," he rolls sideways and turns his back to his son, "Don't ask me anymore, Jack."

"But, Pa, who are you worried about?" Jack ponders what his Pa has said and the expressions on his face and tries to deduce. He reaches a strange conclusion. "Why are you worried about me, Pa?" But Sherlock is already asleep.

I put everything Pa has told me in my Mind Palace, for storing. Lots of things don't make sense. Pa is always careful and I never see him hurt himself, so where do bruises come from? Not from sleep. And if Pa can dance so well, how can he be so clumsy? Answer: Need more data. For the past two days, Pa has had more trouble moving around than usual. He is sadder and cross. He looks away when I look at him. He is afraid for me. Perhaps he thinks Chain will get me too? But I won't have Chain around my leg, because I will never try to leave Room. I don't want to be half-real like Old Magnussen and the Witch.

I take my piece of paper to wardrobe and my dictionary and I try to spell. When Pa wakes up, I show him my paper. It says 'Jack's Mind Palace'. Pa tells me how proud he is and we pin it inside Wardrobe. I'm learning fast.