Thanks for your reviews. I know you're all eager to know what happened to Rose ... and I'm afraid you'll have to wait just a little longer.

The Doctor opened his eyes, to find to cold, yellow eyes of a Demintorian staring right back through the eye-holes of its long black cape.

"Hello Doctor," it said in its husky voice. "You've changed a bit since we last met." The Doctor shuddered at the memory. That was when a group of Demintorians had threatened to take away his supply of jelly babies if he didn't do what they wanted. Luckily he'd outsmarted them then. But what did they want this time? He looked around his surroundings. He appeared to be in what looked like a basement. However, it was filled with Demintorian technology.

"Where's Martha?" he asked.

"Ah yes, that girl you were with," said the Demintorian. "My associates are keeping her company."

"Just let her go!" cried the Doctor.

"But Doctor, that would ruin the point of this exercise," the Demintorian said with a twinkle of evil in his eye. He then turned to the doorway. "Bring out the girl!" Two more Demintorians brought a terrified Martha into the room. She tried to struggle, but it was no use.

"Place her on the table," directed the first Demintorian. Martha was put down on a table in the middle of the room, metal clasps securing themselves around her wrists and ankles. The first Demintorian then pressed a button on the side of the table, which activated a large laser to come down from the roof. The laser was aimed directly at Martha's heart. Martha screamed.

"You can't," said the Doctor. "What's she done to you?"

"But that's the joy of being a Demintorian Doctor," the Demintorian said. "To mentally torture people by giving them the hardest decisions that they'll ever make ... it's what we do for fun!"

"So what do I have to do for you to let Martha go?" asked the Doctor. He captured a glint of the Demintorian's silver teeth, smiling beneath his cape.

"I'll tell you what you have to do," it said. "Our race has been observing you for a while now. We've watched you, but alas, we've never had the chance to capture you. During these observations, we noticed a companion of yours that you seemed to value very highly. A blonde girl." The Doctor's eyes widened.

"Ah, you know of whom I speak," said the Demintorian. "It is obvious that this girl is no longer with you. If you want your current companion to live, this is what you must give us in return – your memories of the blonde girl." The Doctor gaped. He knew the Demintorians were cruel, but to do this…

"Doctor, what are you waiting for!" yelled Martha. "Just do what they say!"

"But … Rose …" said the Doctor. "She … she …"

"She's gone Doctor!" said Martha. The Doctor turned to face the Demintorian.

"This is an impossible choice," he said. "Rose may be gone, but the only way I can keep her alive is in my memories. Whatever I decide, one of my companions will die."

"And you must make a decision Doctor, otherwise we will wreak havoc on this world," said the Demintorian. "You must decide which girl means more to you." The Doctor turned from Martha to the Demintorian, frantically trying to make his decision.

"But could I allow myself to do it?" he said. "Could I take my memories of the girl that comforted me after the Time War, the girl that helped me to live again, the girl that I danced with … and just get rid of them?" He looked into Martha's eyes. "But then again, could I make a decision to let someone I care for die?"

"Oi, what about the stuff I've done for you?" asked Martha irritably. But the Doctor wasn't listening. He stared into space.

This is an impossible choice, he thought miserably. And yet, the more his mind raced trying to think of a logical answer, the more he realised that this wasn't something you could choose by weighing up the pros and cons. The decision had to be reached instinctively. And thought it hurt to admit it, as soon as the Demintorian had told him his choice, he'd known what he was going to do.