There’s actually a few reasons he hasn’t shared the journal just yet in the actual Brothers Apart storyline! (In Brothers Lost and Brothers Consulted, Dean has, on more than one occasion, stolen Sam’s journal with varying results).
In the beginning, Sam didn’t know if Dean was the brother he remembered. It was well over a decade since they’d seen each other last, so he took it slow. The journal was one of the things he kept private, and Dean respected that.
Later on, as their bond came back, and they grew to be a team, Sam discovered that without something to magnify his journal, Dean can’t read it. The tiny handwriting in it is too small for Dean to read, and it would feel plain awkward for Dean to sit there with a magnifying glass the entire time they’re looking through it.
If Sam ever gets a chance with Dean at his scale, he’d love to share it with his big brother…
The younger Winchester was sitting in a corner, his lap once more covered in the scattered papers that made up his journal. He wasn’t writing in them at the moment, but instead carefully reading through. As Dean watched, Sam brushed his hand reverentially down one to smooth the wrinkles on it, then set it to the side.
After a moment’s consideration, Dean left the box of raisins against the wall, giving it an ‘accidental’ kick for the way it tripped him up multiple times in the cupboard. At this rate, neither of the humans in the flat would think he could slip around undetected.
A loud guitar riff cut through the room, startling Sam in his seat and nearly causing him to scribble across his current page. They rarely got any phone calls, so it was a shock to hear. Sam turned towards the bathroom, where Dean was brushing his teeth (or so Sam assumed from the noises he could hear). “Hey, Dean!” he hollered, working hard to project his soft voice across the gap between them. “Phone!”
After a muffled reply from Dean, Sam got up and wandered over to the phone, one of those new smartphones with a touch screen that made it easy for him to use at his size. He smiled when he saw it was Jacob, but before he could hit the button to answer, Dean was stomping noisily over, trying to wipe his face off with a towel. Sam made a face. His experience with motel cleaning crews didn’t make him eager to use any of the towels in the room.
Dean’s hand swept down, scooping up the phone while Sam was offered his other hand in a far more careful motion.
Timeline: After moving into 221B Baker Street and before the first story
Sam ran along the tabletop, his pulse thudding in his ears as he went.
Another day, another supply run.
Of course, this time was a little different. With Dean’s odd ability, they’d been able to track down some pencil lead for Sam to use to write with, always a hard-to-find commodity even here, in a flat with belongings strewn haphazardly about and a vast treasure trove of supplies for people Sam and Dean’s size.
It was a bit of a risk, with the humans still in the building, but Sam didn’t want to risk the snapped lead vanishing when one of them cleaned up. He’d been able to find enough scraps of paper to form a haphazard journal, but needed something to write with. His old bit of lead was nearly ground to dust.
Two shards of the tip of a pencil were nestled in his leather satchel, bouncing against his side as he ran. Sam made it to the edge of the table, peering down at the floor to see where Dean was, waiting for him to get down. They couldn’t afford them both out in such an exposed place, so Dean, the weaker climber, stayed on the ground.
Instead of using his hook and thread to climb with, Sam took advantage of the chair that was leaning against the edge of the table. A black jacket was draped overtop the chair, and offered Sam more than enough handholds to get himself to the floor. He cautiously began to pick his way down the fabric, occasionally glancing at his surroundings.
Just then, the stairs between the flat and the one upstairs creaked as John descended from his room, tugging on a jumper as he went. He needed to go to the bank, run to town for a few things, and was considering a stop at the pub later that night for a well-needed drink.
And with Sherlock shut in the bathroom preoccupied with his bioluminescent bacteria cultures, without a case on, John had a rare opportunity to slip away.
John was straightening his short, sandy hair, mussed by his jumper, as he entered the main area of the flat.
Sam stiffened, and Dean didn’t need his signal to know it was time to dive for cover. The older Winchester vanished behind one of the sturdy table legs as the floor shook under his boots, unable to do anything to help Sam out without taking an even greater risk of John spotting them.
With his knack tingling a sharp warning, Sam looked up at the table. It was too far up for him to risk climbing back up and searching for a hiding spot. The floor was too far down to reach in time if John decided to come into the kitchen.
Which left him one option.
Sam let go of the fabric he was clinging too, plummeting straight down into the dark folds of the pocket which yawned open beneath his feet.
John paused at the door when he noticed his coat wasn’t on its usual hook. It wasn’t on his claimed armchair in the living room either, and that’s when he remembered he’d left it in the kitchen. With a sigh, he rounded the corner and approached the table, never spotting the small shadow that ducked behind a table leg, only leaning out slightly to keep an eye on him.
He bent to retrieve his gloves from the pocket first, without even the slightest suspicion that there was someone inside, dodging fingers longer than he was tall.
Which, from the second John’s hand entered the pocket, Sam was.
His first warning was the cold shock that ran down his back from his knack. Sam’s eyes widened in the darkness as he saw a shadow fall over the light that leaked in from the kitchen. Hide. He had to hide better.
In the pocket with him was two black gloves, providing the cushioning for his landing. Without them in the way, Sam would have tumbled all the way to the bottom of the pocket. With John so close, that’s what Sam needed. More distance.
Squirming around the gloves, Sam put them between him and the opening of the pocket. Long fingers reached in, groping around for the gloves that were stuffed inside for safekeeping. Sam spotted them, and his breathing sped up.
Memories of his first week cursed came flooding back, and his desperation to escape John’s grasp only grew. Sam twisted around, kicking the gloves further up in the pocket interior while he slid all the way to the bottom. His first experience with hands like that, his shoulder was dislocated. The last thing he wanted to do was relive that, and it was all made worse by the knowledge that John was a doctor, more than qualified to dissect either brother if he got them into his hands. All the experiments around the flat always drove that truth home to them when they were out.
Finding the gloves right away, John’s fingers dove straight down to achieve a secure grip on them. A knuckle brushed against Sam’s jacket, the contact going unnoticed by the human as something else caught his eye.
“Dammit, Sherlock…” muttered the doctor, straightening and placing the gloves on the table.
“I said, keep your cultures off my things!” John strode toward Sherlock’s work table, delicately plucking petri dishes from his laptop, which his flatmate had a habit of commandeering. With a huff, John tucked the computer under his arm and rushed it upstairs to scrub it and lock it in his bedroom before he found anything sprouting on his keyboard.
Sam couldn’t believe his eyes. He remained flattened at the bottom of the pocket, listening to the distant footsteps as they thudded up the stairs of the flat, waiting to be sure that John was actually leaving, even after touching Sam’s jacket, the closest he’d come to a human in years. He’d thought it was all over right then, the hand would shift position, making him tumble into the human’s grasp and sealed into a fist by fingers stronger than his entire body.
Instead, John had pulled away and stalked across the flat yelling at Sherlock, and Sam was wasting his opportunity to escape thinking about it.
Quickly pulling himself to his feet, Sam scaled out of the pocket in record time. Dean was down by the table leg, staying close to cover in case the human came back. He didn’t have Sam’s uncanny knack of knowing when someone was about to come into the room and spot them, leaving him more vulnerable than Sam.
Not that it was doing Sam any good today.
Sam used the thick threads of the jacket to climb down, dropping the last few inches. His arms continued trembling from the close call, shaken. Dean’s arm was on his back to keep him steady the moment he got down, but seconds later they were running across the floor.
It was time to get out of sight for the rest of the day. Their luck had been pushed the the limit enough that week.
What Castiel can or can’t do will have to wait for his appearance in the stories, if and when he comes. Can’t be giving away trade secrets, after all 🙂
But as for a new journal and new clothes, Sam has both of these things. In A Schism of Fire and Water, Sam was given a journal from Dean for his birthday (just because it’s made for a dollhouse doesn’t mean it isn’t useful), and Krissy made him new clothing that Walt and the others gave him.
Pointing towards the dusty piles of boxes and antiques, Dean explained. “The last place we saw them was in the piles of boxes. It’s our best bet to start, and we can branch out from there. Hopefully, with Jacob out of the picture, they’ll reappear. I really think we were getting somewhere last time with the journal.”
“At least the journal’s in one piece,” Sam murmured as his hand strayed protectively to his bag. It was the only one of its kind he’d ever seen, and he didn’t want to risk it. He already had to write in the margins and use up every millimeter of space so he didn’t risk running out of blank pages. With Dean’s shenanigans, he was going to be left without a journal inside of the year.