Author's Note: Woops got in to a new fandom. Anyways I wrote this so here you go I guess. I don't own Who.
The first time that she'd seen the Doctor's room on the TARDIS, Martha was rather surprised. Though she didn't know what she was expecting, she was greeted by a rather plain little room. There was a single-sized bed with blue and white checkered sheets, a night table and a lighting fixture on the ceiling. It was barren compared to her room - it was barren compared to any other room in the whole TARDIS, for a matter of fact.
And she really shouldn't have been in it.
Despite knowing that, she stayed in there anyways. She'd taken a sick day from duties having come down with a flu, so the Doctor was out. She'd been exploring, and she had been curious.
This was still a bad idea, though. If the Doctor came back now, he might get mad at her. Martha knew that wasn't likely, but there was the chance.
Her stuffed up head didn't listen though and, rather than go back where she came from, she wandered forward in a slow pace and sat down on the edge of the Doctor's bed. She rested her hands, clasped together, in her lap and gazed slowly around the room.
There was another thing here, she discovered. Sitting atop of the night table was a small piece of what looked like film - a picture. It was upside down, leaving its shiny white back to face her.
Martha regretted what she did next as soon as she did it.
Slowly, she picked the piece of film up and flipped it over before dropping it right back on to the table with its picture still up. There, smiling and beautiful in a picture on the night table of the man she loved, was a picture of a beautiful little blonde girl with her hand extended in the direction of the camera. There was a space-age city behind a lake and a grassy field.
New New York, Martha guessed. He'd brought her there, too.
She felt the life drain out of her in that moment. She was well aware that the Doctor still cared for Rose, yes, but why did he have to keep a picture of her? Why couldn't she be enough.
Tears had just started falling from her eyes as she heard a knock on the metal door frame. Martha wiped away the stray tears and glanced up towards the doorway.
"What has you here?" The Doctor moved forward in quick, large strides and stood before Martha.
"I was exploring, found your room," she said in a small voice. "Sorry."
"Oh, no need to b-" His eyes caught a glimpse of the revealed picture on his bedside. "Why were you looking at that?"
"I didn't mean to," Martha returned. "I was curious, and this place is just so.. empty." Her tone was flat.
"Ah, well, the rest of the TARDIS isn't."
"I know."
"Okay, well if we've had this chat, let's go!" He turned and had his arm up and ready to move when Martha interrupted him.
"If you could, would you have her?" Martha's tone was filled with deep dismay and lackluster, and there was a slight pause before she continued. "Would you have her here instead of me?" The young woman bit down on her lip as she glanced up at the Doctor. The response wouldn't be the one she wanted, she figured, but she had to ask anyways.
"I can't have her," was his response. He shook his head and met Martha's gaze.
"No, but if you could?"
The Doctor's expression turned solemn, and he turned back to face Martha. He pondered for a second.
"Martha," he sighed. "I would have her here in a heartbeat if that was an option, if she could be safe here. I'd spend a thousand lifetimes with her, I'd take the forever she offered me."
It was still a thought that pained him, having to leave his Rose behind. Every time Martha related something to her, every time she brought Rose up, every time she sassed him about her (yeah, he heard it) it hurt him. He wasn't used to feeling this way, especially not about fragile, time-limited humans. He couldn't say that he liked it.
"You love her," was all Martha could respond.
Doctor's gaze averted Martha's saddening one as he fight for words.
"Martha, I-" know how it sounds, but I can't have that. He would never be able to have to - he'd sealed the rift that allowed the travel between universes, and he'd done it on purpose. He'd known what he was giving up.
"No, you don't need to explain yourself, Doctor," she sighed. "I just... I had to ask."
Two days later they had ended up at the end of the universe, where others sought Utopia, and once again the Doctor had to save the world - this time from the Master. Martha herself had played a strong role in this, bringing everyone together to aid the Doctor. She had, at least partially, saved the world. She could be proud of that.
It was after that event that Martha left, knowing that there wasn't much hope for her with the Doctor and that she needed to do what was best for her. It hurt , it hurt her more than anything, but there was no point in sticking around and being nothing to someone that she loved.