AN: For those of you reading my other story, don't worry, I'm still working on the next chapter. I just got this idea for a story in my head and it was begging to be written. I do have to warn you that the majority of this was written at three in the morning. I've made a few touch-ups, but those were made at three in the morning the following day. This is what happens when I have three day weekends.

Disclaimer: I own no part of Castle or its characters, nor will I by the time I finish this story.

Castle returned from the break room where he had been talking to Ryan and Espo about their latest case, two coffee mugs in hand. He had been gone for only ten minutes, Beckett grumbling something about paperwork. The case had been solved only the day before, and it had been a late night. As it had been late, they hadn't been able to get a warrant for their suspect's arrest until this morning. Now that the man was in holding, all that was left to do was paperwork.

When he sat down in his chair, he noticed that Beckett seemed to have nodded off. Her head was propped up on the heel of her hand, and her hair was shielding her face, the same position she had been in when he got up to get coffee. From a distance, she probably looked as though she was focused on the form in front of her, and the only reason Castle had known she was asleep was because of her lack of response when he set her mug down on her desk. He wondered if she had fallen asleep before he had even gone to the break room.

Gently, he gave her shoulder a small shake. She let out a small grunt in protest, but her eyes fluttered open. Squinting, she raised her head and look at him.

"Castle?" she asked, her voice thick with sleep.

"You dozed off, I'm not sure how long you've been out," he told her, then smiled. "Don't worry, I won't tell Gates."

She nodded her thanks, yawned, then sat up in her chair a little straighter. "What time is it?"

Castle checked his watch. "About a quarter after four."

Beckett's eyes went wide, and suddenly she was out of her chair and hurriedly putting things away.

"Beckett, what's going on?"

"I have an appointment at four-thirty," she explained as she threw pens into the cup on her desk. "Damn it, I'm going to be late."

Castle was out of his chair in an instant. "I'll clean up, Kate. You worry about your appointment." He knew that it had to be important for her to be rushing like this, so he was ready to give her as much time as possible.

"Thank you," she said as she reached for her purse. Unfortunately, in her haste, she only grabbed one strap and the contents spilled out onto the floor.

Muttering obscenities, she crouched to the floor and started to throw them back into her bag. Castle was only a second behind, and once everything had been replaced, she was half-jogging towards the elevator.

At least, they thought it had been everything.

Castle lingered a moment longer, and when he glanced down as he stood, he noticed the edge of a notebook peeking out from underneath Beckett's desk. He grabbed it, then turned towards the direction she had gone.

"Beckett," he called. "You forgot your…" It was too late. By the time he had shouted, the elevator doors had closed. He looked stupefied towards the elevator, then turned back to his partner's desk, starting on putting all of the forms back into folders, leaving the notebook in the middle for him to decide what to do with later.

"Mr. Castle," Gates' voice came from the door to her office. "Where has Detective Beckett run off to?"

"She had an appointment, sir," he responded. He had expected her to ask what the appointment was, but the captain nodded at the information.

"Yes, she mentioned having to leave this morning. I take it she's running late?"

Castle nodded quickly. "She got caught up with paperwork and lost track of time."

"Well, at least she was working," Gates mused. "You can go home now, Mr. Castle."

"Yes, sir," he replied, trying to keep the dejection out of his voice. Gates took any opportunity to get him out of the precinct. The boys poked their heads out of the break room, having seen the entire scramble.

"You leaving for the day?" Esposito asked as he walked back to his desk.

"I told Beckett I'd clean up her desk, but then I'll be gone. Probably catch up on some writing."

"Are you coming by for lunch tomorrow?" Ryan asked.

Castle nodded. "Sure. Want me to pick up Chinese for you guys?"

The pair let out happy sighs. "Thanks, man," Esposito said.

As the two detectives got themselves situated to do their paperwork, Castle replaced folders back into the drawers he knew them to always be in, then looked back at the notebook, conflicted. He wasn't sure whether to leave it here or not. Thinking that it was likely something personal, he opted to take it home with him, then call her about it later. Odds were that she didn't want people looking at it, and if he were to leave it on her desk, anyone could pick it up, or maybe the boys would get curious about what it was since no one had ever seen it before.

"See you tomorrow, guys," he called before he walked towards the elevator, Beckett's notebook tucked into his jacket. Ryan and Esposito called out their farewells, and he turned to leave.

Since Alexis was at a study group with her friends, and his mother was out doing whatever she does when she goes out, Castle had the loft to himself. He spent much of his time pacing around the living room, Beckett's notebook sitting in the middle of his coffee table. He should text her, let her know where it is in case she misses it, but he couldn't bring himself to do it. He wanted— no, needed to know what was in that notebook, but he didn't want to invade her privacy. If it was something personal, there was a good chance she wouldn't want to speak to him if she found out.

A glance at the clock told him that he had been fussing about this to himself for nearly half an hour, and finally, he came up with a solution. He'd open the front page, read the first few words to figure out what it was, then never open it again. It would be easy.

He picked it up and held it in his hands for a minute. Taking a deep breath, he flicked open the front cover, saw two words and immediately snapped it shut. Two words. Two words that made his world stop spinning for a moment before his mind started whirring with possibilities for what they meant:

Dear Castle...

They only made him want to read more, to know exactly what she had written on the rest of the page, the rest of the journal. He wanted to know what she could have possibly written, what she was writing to him. He wanted to know everything she had to say to him, what could be so important that she felt the need to write it down. He knew he shouldn't, so he didn't.

For about an hour.

For an hour, he sat down and wrote a few decent paragraphs, but his eyes kept wandering to where the notebook now lay on his desk. After an hour, he gave in. He opened up the front cover, and read the first section.