For any Pratchett fans, you know where I got the idea of the Devouring Dark from. It's not a complete rip off (I hope) but it is similar enough that I felt the need to mention it. Anyway...duh duh duh...
The effect was instantaneous. The women in the crowd all shrieked and made the sign to ward off evil. The men looked over their shoulders, ready to run as fast as possible. And Andy's hands fell to the earth in front of her, her back arched and she screamed and screamed and screamed.
The Doctor heard a noise behind him. Matros was standing there, his eyes wide in shock as he watched the girl he had sworn to protect writhe on the ground in pain. He looked up into the Doctor's face. The Doctor didn't like what he saw there.
"What have you done?" Matros spat at him. The Doctor couldn't think what to answer, but he didn't need to. A few seconds after Matros had spoken, Andy stopped screaming. The silence that followed was tense and fearful. But it was also full. Something was there. Something that hadn't been there before.
Andy was still on her hands and knees, but now she began to stand, her face still tipped towards the ground. The mob around the well backed away with every movement she made. Matros' breaths came quick and shuddering. And the Doctor, ever the fearless man, took a step closer,
"Andy?" he said, hoping beyond hope that he was wrong.
"No," the voice that hissed from Andy's mouth was nothing like Andy's. It was a harsh yet slithery sound, almost like a snake's voice, and it rang with the echo of ages and centuries long gone. Andy's head began to rise, drawing in breaths as though she had never breathed properly. Her irises, which had once been that mesmerising haunting green, were now empty and black as pitch, yet they glinted with an insatiable hunger. Her mouth twisted up into a hideous smile, an expression that should never have crossed Andy's face. It made her look evil and lawless, "She's gone. It's only me now." And the thing that was now Andy began to chuckle.
As the laughter rose, the spell of inertia broke. Women screamed and hurried away to their houses as quickly as possible. The men seemed torn of whether to follow or to stay and defend their homes. And the Doctor swallowed, a huge lump in his throat nearly choking him. But he had never let anything beat him before, he wasn't about to start now.
"So…you're real then." Hardly the best start, but it always helped to keep it simple. The entity smirked,
"You were so blind. You didn't want to see the monster, did you, Doc-tor," the way it dragged out his name made him shiver, "You didn't want to believe that this innocent little girl could possibly house something like me inside her. Oh, she was so weak. The first time she came to me, she came almost willingly. Desperate for a friend, desperate to be found. She wanted to be noticed. She wanted…to be loved." Here the entity sneered, "So easy to tempt her. To tell her I would cherish her. I would help her to be noticed. All she had to do was welcome me." It continued to smirk at the Doctor, seemingly waiting for something. But he'd already figured it out.
"You started the rock-falls, didn't you?" It gave a hissing laugh,
"Oh, very good. I thought it might take you longer to figure it out. So simple. A little push there, a little suggestion here, she did it all on her own really. She wanted to be noticed. I gave her something for which she could be useful. She was certainly not ignored afterwards."
"But she wasn't loved either." the Doctor snarled. The entity shrugged Andy's shoulders,
"You can't get everything in life. You of all people know that, don't you, Time Lord." And here it fixed him with a look of utter hunger. The Doctor was suddenly rooted to the spot in fear,
"You don't know anything about me," he said, trying to sound angry, while fighting bone chilling terror. The entity laughed, a high pitched laugh this time, making everybody who was still listening shiver,
"You forget your stories, Doctor. The Time Lords may be old, but I am even older. Perhaps not quite as old as they say, but definitely older than you. And I have whispered into the hearts and minds of every one of my hosts, and learned their weaknesses and their pain. Of their poor little hearts, their loneliness, their loss, their betrayals. Such power for me, there is nothing quite like the taste of a diseased mind. They tell me their desires and I…"
"Give them exactly what they don't need," the Doctor countered, "You use their pain, their weakness against them. You drive them insane." Again, the entity shrugged,
"Then you shouldn't invite the monster to dinner, Doctor. And you definitely shouldn't have called me." The smirk returned, in all its grotesque glory.
"Why? What can you possibly do to…?" And suddenly his eyes widened as everything suddenly made sense. The entity laughed again at his expression,
"I have her power, Doctor. When I absorbed her mind, I absorbed her power. I can do everything she could, and more, because I do not fear the consequences. You know I have those vines around your ship. I'll suck her dry of power if you don't take me where I want to go." Trying not shiver as he thought of all that power, all that life, inside this ages old darkness, he asked,
"What do you want?" A triumphant grin covered Andy's face, as grotesque as the smirk had been,
"I want what she wanted, to get off this rock. I want what she wants, to travel the universe. Imagine it, Doctor. Every living person, from the beginning of time right to the very end. So many hosts. So many events that could have been changed, had people only the will to do it. So many civilisations that would never be formed because they would not survived, so weak were they. So many things I will change with each new host," here she looked right into the Doctor's eyes, "and you shall deliver me to each of them."
It felt like a punch to the gut. He couldn't do this, he couldn't use the TARDIS, his Time Lord powers in this way. He couldn't deliver this ancient evil to all of the important places in history, just so that the time lines, and perhaps the laws of history could disintegrate. He couldn't. He wouldn't.
"I won't." The black eyes narrowed to slits. The mouth twisted up into a horrifying grimace,
"If you will not help me, I will use her power to tear this planet to pieces. All of these people will die, even the innocents who don't even know what is happening here. Your TARDIS will be lost forever, floating endlessly in the vacuum of space. And you, the Last Time Lord, shall die on this pathetic rock, in cold blood, with no one to remember your name, or even erect a headstone for you." The entity was nearly spitting in rage. The Doctor wanted so desperately to save the TARDIS, to save Merrick, even Matros, but he wouldn't do what the entity asked of him. He would rather die.
"No." He glared his defiance back at the creature. The entity bared its teeth,
"So…urgh," The Doctor stared in shock. The entity's body had jerked, as if someone invisible had just punched it in the gut. Now it was dry heaving and choking, as if it was about to be sick. Its eyes had opened wide in shock and, in the light of the dying sun, the Doctor could have sworn he saw a flash of green. Suddenly its knees buckled. It ended up on hands and knees, just as Andy had when it had…no. It had said…but of course an evil entity would never have lied, would it?
"Andy?"