Martha, knowing she would be intruding, and no one would ever accuse her of it, nonetheless stayed in the shadows. The Doctor had been a right energetic typhoon, working tirelessly all night...or what passed for night in space. His habit of speaking to himself - or to the ship, she supposed - had filled the control room with ceaseless commentary and one-sided conversation, and it amused her to relax in a chair in the corner and just listen to him being happy.

"This wire...ah-ha! - now, where's that diode..?" The Tardis must have zapped him then as he let out what certainly sounded like a curse. It was in no language she recognized, but tone of voice needed no translator. Nothing daunted, he never stopped his machinations for even a second. She had thought at one point about offering him some food or drink, but realized that hope and love fueled his body better than anything meager refreshment could achieve. Instead she sat there, quiet and unobtrusive, soaking up the happy mania of the atmosphere and watching the Doctor rush here, there, and everywhere talking to his ship.

"So the coaxial goes...over here...and then this switch...and that...and it's all hooked..."

After what seemed like hours, and probably was, he'd put the finishing touches on his creation. Turning to her, eyes shining, he grinned.

"Well, then, this is it! Now to see if it works. The Tardis says it will, but then again she's been known to be wrong..." ZAP! "Ouch! You! It's true and you know it! Now, you wonderful machine, let's power it up!" He threw a switch and turned a dial, and for the longest time nothing happened. Martha was about to make a comment when she gasped instead. In the center of the open space in the console room, a shimmery, ghostly image of a group of people faded into being.

An older couple and a younger couple sat around a table, obviously deep in conversation. The younger woman was holding a baby that Martha guessed couldn't have been more than a few weeks old. Difficult to tell, though, as the view faded in and out like a low-reception telly. She heard the doctor's breath catch and though she thought later it should have dawned on her before then, she suddenly realized who it was they were watching.

"Is that..?" she asked quietly. His wide eyed gaze, like a parched man staring at an endless sea of water, was answer enough for her. She wouldn't have needed to hear the reverently whispered "Rassilon" to know that the young woman reclining in the straight-backed chair with such apparent ease was the one he'd given his heart to.

"Audio...I need audio, need to hear..." He paused for a moment and Martha assumed he was listening to his ship's response. Her guess was confirmed a moment later.

"More power? Well, then, take it from me! Just get me SOUND!" His knees buckled suddenly and she was about to run to him when he climbed to his feet. "Not funny, you." Pause. "Yes, but I didn't say to drain me like a plasmavore after a hunger strike, now did I?" Anything else he might have said to the Tardis stopped abruptly at the first sound from the foggy image.

"...why the worlds are colliding with you in the center."

"I'm the focus? But why?" the girl protested. Martha saw the Doctor shudder, could see how the strain of somehow powering this weird connection was leeching his strength. But when he spoke, his voice was steady, wry, and full of life, and Martha nearly squealed at the sound.

"I believe I can answer that."

All heads swiveled in the direction Martha supposed he was appearing to them from. For the first time she realized the sheer amazing truth of the matter, that they were truly in different dimensions, and speaking together because of determination and love. She didn't realize she was crying when the young blonde - Rose, she knew now - passed the baby to the other woman at the table and vaulted over her chair to stand before him.

"DOCTOR!" She stopped short, tears glistening on her lashes. "Oh god...is it really you?"

"Hush, love," he murmured with a tenderness Martha had never in her life heard from anyone. She realized that right here, right now, there was no one in the world for the two of them except each other, and she felt a bit like an intruder.

"Yep, it's me. Gotta thank the Tardis - she locked onto your mind and, with a bit o' jiggery-pokery, opened this channel."

"But, are you burning another sun? How are you powering this?"

"She's drawing it mostly from me, so I have to be quick. You are the focus because you are an energy paradox. Humans cannot survive touching the Vortex. Your biology should have died instantly. But you did the impossible. You survived. And the small traces of Vortex energy that remained bonded to your cellular structure. You're a walking battery, Rose! And that is what is fueling the convergence."

"Doctor...you sound strained...you can't do this! You'll kill yourself! And I swear, if you regenerate for this, I'll wait until you're done and regenerate you again!"

Martha watched as the Doctor raised his hand to trace his fingers along skin he couldn't feel.

"I had to see you again. It's worth the strain. But I have to go before it rips me apart."

"Wait! You said I'm a battery, and I'm linked to the Tardis!" Rose closed her eyes and to the shock of everyone in both worlds, a faint golden glow suffused her body. The Doctor looked terrified.

"ROSE! NO! You can't!"

"Yes I can," came the impossibly calm reply. "If I cannot go to you, I shall bring you to me."

The Doctor moaned and Martha felt the ship shudder like never before.

"Hold on to something," the blonde said, and the Tardis' passengers barely had time to follow the instructions before the universe exploded.