Thunderstruck, she watched him go. She couldn't believe it. Almost in a trance, she reached down and picked up the torn pieces of paper and put them in her pocket. Then she stood there for a moment, waiting for him to return, waiting for him to come back and say it had all been a joke. When he didn't, she began to realise how much she had taken it for granted—that no matter what happened, no matter what the circumstance, the Doctor would always help her, if he possibly could. She began also to realise that she took a lot of people for granted: her mother, Pete, and Mickey. Especially Mickey. She felt her face turn hot with shame.

Her thoughts turned again to the Doctor--that bitter, old Doctor who had abandoned her to her fate. She decided this must be one of his last regenerations. What had made him like this? What had caused so profound, so awful a change? Was it a lifetime of helping people and facing their ingratitude? The accumulated trauma of death, pain, and loss? Or was it just the long, long years of loneliness? The tragedy of it was overwhelming. Rose was alone, utterly alone in this place at the end of the universe; and she fully expected to die there. She wept; not for herself, but for the Doctor--for what he would become.

"Rose?"

She looked up. Standing before her was a man in a green velvet frock coat with a halo of long ringlets and the kindest, bluest eyes she'd ever seen. "Doctor!" she cried, and flung her arms about him. "I'm sorry, I'm so sorry, I didn't mean what I said, I was horrible to you, please forgive me!"

"Wait, wait, shh," he said. "It's all right, really." He caught hold of her chin and tipped her face up to his. "Don't be silly. Do you really think that's the first time my interfering has got people angry at me?"

She laughed and sobbed in reply. "I'm so glad you're here--I thought you left ages ago."

"Er...well..." he said. Rose thought she detected a sheepish expression.

"So...what's been keeping you?" she asked.

"I..er...I couldn't find my TARDIS. I forgot where I--well, with the chameleon circuit fixed, it was impossible to find in the dark!"

Rose couldn't help herself. She was doubled over in laughter. It was so funny--and so incredibly lucky!

The Doctor shot her a reproachful glance and continued, "Now that the lights are on, I might have a better chance...well, never mind about that, what about you? Why are you still here?"

Rose handed him the torn note and managed to pull herself together enough to describe the events of the evening. "What does it mean, the 'Big Rip'?"

He didn't reply. Instead, he found his pencil stub and started doing calculations on the back of the note. "That can't be right," he muttered several times, scratching out his work and starting again. Finally, he threw his pencil down and covered his face with his hands, "This is horrible. How could I have been so blind?"

Rose picked up the paper. She couldn't make sense of the calculations, but she tried to read the final number. "One thousand twelve?"

"No, ten to the twelfth power years. A million million galactic years."

"What does it mean?"

"My universe should have spent trillions upon trillions upon trillions of years—10 to the 142nd power galactic years, to be exact—slowly aging and cooling off, same as the rest. Instead, because of the excess dark energy created by the Kaleds, time and space will be catastrophically ripped apart in a mere million million years. Galaxies, stars, planets, people, everything annihilated. That is the 'Big Rip.'"

"A million million years...that still seems like a long time," said Rose.

"No—it isn't," he said, grimly. "It's as if the entire existence of the Earth—10 billion years—were reduced to a single second. No—that doesn't even begin to capture the enormity of what has happened. I saved the Time Lords but destroyed the universe."

"You?" Rose stared at him in disbelief.

He gazed past her, unseeing, his face aghast. "The Time Lords set me the task of altering the Daleks' development or destroying them. I chose the latter. Because of me, Daleks don't exist and Kaleds do. But at what cost?" He squeezed his eyes shut. "What terrible, terrible cost?"

There was a sudden, metallic groaning noise. The lights flickered and the floor seemed to ripple. Rose seized the Doctor's arm, "Don't change!"

The Doctor hardly seemed to notice that anything had happened; although he did look at her in confusion and say, "What do you mean, 'don't change'?"

"I meant—never mind. Look," said Rose. "We've got to get out of here. The...other Doctor said that I was causing the problems here and I have to get off the restaurant."

The Doctor nodded absently, but didn't move. Rose pointed down the corridor. "I think you parked the TARDIS this way." He didn't answer her. She studied his face for a moment, trying to read his inscrutable expression. "Doctor? What is it?"

And then she remembered what the Doctor—this Doctor—had said to her at dinner: "I don't know your Doctor; but I know what would happen to me if a failure of mine caused so great a catastrophe. His mind is broken—it must be."

She knew what she had to do. "Just—just wait here one second."

Rose went to the Proprietor's desk and found the pencil. On the last space of paper left, she wrote a quick note. She pressed the paper to her lips; and then put it down on the desk. She went back and took the Doctor's arm. "Come on, we've got to go," she said, coaxing him down the corridor.

Halfway down, they heard the sound of an argument in an adjoining corridor, just out of sight. Rose recognised the Proprietor's voice. "Didn't I tell you idiots to stay OUT of the public areas? It's the kitchens for you, indefinitely—"

Rose suddenly had a terrible feeling about this. "No!" she yelled. "Proprietor, get out of there!"

"WE DO NOT AC-CEPT OR-DERS FROM IN-FER-I-OR RA-CES! RE-SIS-TANCE IS USE-LESS! EX-TER-MIN-ATE! EX-TER-MIN-ATE! EX-TER-MIN-ATE!"

There was a flash of light and screaming. Rose started to run away, but realised the Doctor wasn't following her. He was looking to-and-fro, wild-eyed; and he was murmuring to himself. "I didn't...I didn't have the right..." Then, to her horror, he began to stagger towards the Daleks.

"No, Doctor!" she whispered urgently, but he didn't hear her. She grabbed his hand. "Don't go that way, you'll be killed!" Still he didn't respond. "Doctor," she pleaded, "help me."

For a split second he hesitated; then he turned and looked at her. His eyes had cleared; they glittered like polished steel. "What are you waiting for?" he said, crisply. "Run!" Hand-in-hand they sprinted away.

Several turns later, they were in a large room that Rose didn't recognise immediately. However, from the layout, she supposed it must be some sort of hangar for TARDISes and other timecraft. In what she knew was really a vain hope, she began searching it for any sign that her Doctor had arrived. But his blue police box was nowhere in sight.

"Over here." The Doctor pointed to a faint shimmer in the air. He turned the key in the lock and stepped inside.

"Good, you found it," said Rose. She moved to follow him inside, then hesitated.

The Doctor stood in the doorway of the TARDIS. "Rose, the instability is worsening. We don't have a lot of time. And I've got to wall off my universe before the Rip effects start to propagate and destroy other universes." He extended his arm towards her.

"I know," she said. Still standing in front of the TARDIS, she stared into the open hangar, hoping against hope that she could somehow will the blue box to appear. "I just want to..."

She was interrupted by the metallic groaning sound, even louder and more insistent than before. The floor rippled and the walls began to bend. Suddenly they snapped and collapsed inward. Everything exploded. Just as the destruction was about to swallow her, Rose turned and jumped, into the Doctor's arms. He swung her into the TARDIS and slammed the door shut.

The Doctor flung himself at the control panel. He punched a button—Rose recognised it as the "fast return" button—but nothing happened. The Doctor started to hit the console with his fist; but apparently he thought better of this, and instead placed his hands on the central shaft. "Come on, old girl, come on, you can do it," he pleaded. "Get us out of here!"

The TARDIS shuddered to life and dematerialised.