"Doctor?"
River leaned up against the wall of the house, coughing. She slipped onto the ground as her legs gave out. Jack pulled himself up through the window after her and dropped onto the wooden floor. She pressed her eyes shut and licked her lips, only tasting ashes dry against her tongue. She was starting to wonder if they would even make it out, much less with the Doctor in tow. Jack fished a white square out of his pocket and handed it to her. The texture was somewhere between cotton and plastic. He produced a second one, holding it over his mouth.
"Air scrub," he explained briefly. "This isn't at all what they're made for, but I thought it wouldn't hurt." River nodded gratefully and pressed the scrub to her mouth, inhaling a deep, filtered breath. She watched as dust clung quickly to Jack's and sniffed. They wouldn't last long enough to keep the air clean; a few breaths and the ivory surface was already turning pale gray. She folded hers and slid it into her pocket, determined to save it for the Doctor. Jack looked at her sideways.
"You really care about him, don't you?" he asked loudly. His voice sounded like a whisper next to the boom of the mountain.
"You have no idea." She gave a faltering and exhausted smile. The trek to the house had been far longer and harder than she'd anticipated. Every step might bring the island to splitting apart, every inch of rock and cinders that fell made it harder to move. River had watched the disappearing head of the volcano with anxiety. If the pyroclastic flow started toward them, it would be over. The barrage would bury them without question. A new Pompeii.
Jack lowered his air scrub to cough violently. He clutched at the wall and pulled River onto her feet. "Then let's find him." Farther into the house, the timber creaked and moaned, the supports quaked and quivered. Farther into the house, the ceiling sagged and cracked. River held her breath despite herself.
"We have to move faster." River shook. Jack peered out a window as she struggled forward. "Doctor!" she yelled. "Doctor!"
"River?" Far away, distant and dusty, River was sure she heard her name, almost too quiet to notice. The ceiling above her creaked.
"Doctor!" It was his voice! She knew—
"Mels!" Jack pulled in from the window. Her head whipped around. Before she knew it, he tackled her and they were both recoiling on the ground. A pile of debris tumbled where she'd been moments ago.
"I owe you one," she breathed.
"With the vortex manipulator? Make that two." River hardly heard him. In the same instant she was on her feet again, sprinting toward the sound of the Doctor's voice. Her breath came in shudders.
"Doctor, keep calling." River gasped. His voice grew louder, but it sounded broken. Her name came out in parts.
"Ri-ver—" Jack ran behind her. The house convulsed. River turned a sharp corner and emerged into a crumbling Roman courtyard. The stones that paved it were scattered, thrust through walls. She saw the TARDIS first, doors wide open and wheezing painfully.
"Ri-ver," the Doctor rasped the same way. Relief swelled in her chest and she turned. And broke. Her heart hit the ground.
She ran and dropped to her knees. A column had broken from the corner of the square. It lay across the Doctor, covered in rubble from the roof, crushing his limp form and pinning him to the ground. His breathing was shallow. The weight was shattering his ribs, his lungs, his chest.
"No," she murmured. "No, you can't." She come all this way, she thought she was too late, and now… and now, this. They both looked down as he flexed his fingers. They started to glow gold.
"You're a little late for that," he whispered. River's lips trembled and she bit the bottom one. "Not much good it'll do me anyway, stuck under here."
"Don't you dare." The Doctor coughed weakly. River clenched her teeth. "We're going to get you out. Jack, come here." The Time Agent was standing in the middle of the courtyard, staring up at the volcano. "Jack!" she shouted, and realized her voice was too loud.
The noise had stopped. The shaking, too. It was like the world had suddenly frozen, and she hadn't even noticed. "What…?"
Jack pointed up, silent. River climbed to her feet and followed the arc of his arm. Where there had once been a pyroclastic cloud and a volcano burning across the sky was now a soundless spill of white light pouring downward. Her lips parted.
"What is it?" Jack asked. His voice was the only noise.
"I think…" River gulped, not wanting to say it, "I think it's temporal energy. If it reaches us…we never existed." Jack's brow furrowed. River looked over her shoulder at the Doctor. He was fighting it, but regeneration was creeping on. "So we should move." She ordered Jack to start clearing bricks off the Doctor. She knelt down and brushed off his leather jacket. Half tempted to brush her lips on his ever-wrinkled forehead, she leaned forward, and caution got the better of her. "Just hang on. We'll get you into the TARDIS." She kept an eye on the light from Krakatoa, and glimpsed the Doctor mournfully shaking his head. He closed his eyes.
"She's gone."
River's eyes widened. "What do you mean? Doctor, what do you mean?" He didn't respond. But he didn't have to; his face grew grave. "Jack," she said urgently, "work faster."
River stumbled backward, onto her feet and practically fell into the TARDIS. Her heart was beating desperate against her chest, frantic in her ears. The TARDIS whined in protest as she pulled open the door. Cannibalized. The guts of the TARDIS trailed the floor, hooked across a grid around the matrix. Wires were everywhere. The grates, all open, were flung everywhere. The TARDIS didn't just wheeze, she cried…she screamed. River pressed her hands to her mouth to hold back a gag, and fled. She felt sick. Inside her head, she could feel the TARDIS shrieking, white blinding agony and wrongness. She thought her knees might give out, but the side of the box kept her upright. She took a deep breath and pressed her hands to her ears, forcing the pain to subside. A step forward. Compartmentalize. She separated the part of her mind feeling the TARDIS from the rest of her thoughts.
"You made a paradox machine?"
Jack's head flew up. "A what?" He'd cleared off the bricks and rubble, leaving the column as the only thing crushing the Doctor. River had a sinking feeling that even if they could get it off, it would be too late.
"A paradox reversal machine," the Doctor replied softly. The glow around his hands was brightening. "It's never been done before, but…but we thought that maybe…."
"That man you knew?"
"He was an engineer who specialized in temporal mechanics." The Doctor's voice caught on the past tense. "But Krakatoa erupted… he and his wife, they…" He swallowed heavily. "We didn't quite finish."
"You had better been close," Jack said. He nodded toward the volcano. The temporal energy was approaching the house and speeding up.
"We have to go now," River ordered. "Help me, Jack." She braced her hands against the column crushing the Doctor and shoved. It didn't budge at all. "Jack!" she half-screamed. He shook his head.
"No way we'll get it. Time to run, if you ask me."
River pressed her lips into a determined line. "You don't know him. We have to save him." She could feel the heat of the light spilling over them, burning, erasing. "We have to—" She pushed, digging her heels into the ash and pausing to rub her eyes, whether from tears or soot, she didn't know. "We have to save—" She heaved with all her might, but no movement resulted. She pushed and pounded and punched through the blur ruining her vision until she was forced to lean back against another column, panting hard. The heat from the light was harsh, sharp, cutting into River, and it was bright—brighter than light should be, than light could be, reaching behind her eyes and driving her insane…it was pure torment, she almost wanted to let go, let it divide her existence into nothing and nothing again… But instead, she rammed all her weight at the column.
"Give it up!" Jack called.
"If you knew him-" she spat. The Doctor lifted a glowing hand.
"You have to use the paradox machine."
River shook her head. "You said it wasn't done." His eyes pleaded with her. Time was imploding, the world was ending, the Doctor was dying. "I won't do it."
"River…please." His eyes. Those old, young, broken eyes. "I'm the last one… Please."
She bit her lip and pressed her eyes shut. Paradox machines were dangerous. They had to be precisely balanced. They were terrible and wrong. And he wanted her to use the reverse, something that had never been used, never been built, wasn't even finished.
"Fine." She stood up and strode toward the light, took a deep inhale, and surged into the TARDIS. Through the chaos and the terror of the box's interior she found a little box and opened the lid. She flipped on the switches and rested her fingers lightly over a small red button. She closed her eyes, willing herself to push it down.
"Mels," Jack yelled, trailing off. The light began rush into the courtyard. Its tendrils wrapped around the TARDIS, invading the inside, crawling up the walls.
"River Song, this is it." The Doctor's voice fueled her courage. She pressed her eyes shut and the button down. The world swirled and then, disappeared.
