Previously:

"It's not me that's holding it back. God, this is going to sound bonkers... There's a third entity in my mind now. A symbiotic consciousness that can neutralise the metacrisis for a time."

"But that's wonderful, maybe I can work out a way to make it permanent! What species is the consciousness?" He clapped his hands and grinned at her.

Donna sighed. This was the part he wasn't going to like. "Time Lord."

The Doctor's face became suspiciously blank. "Sorry, what?"


"My symbiote... It's River Song."

He flinched backward as if she had slapped him. "What?"

"I have your wife in my head and she's helping me. That's what is holding back the metacrisis now, keeping it from burning out my mind. She's building up my mental barriers, and redirecting the flow of energy so that it's in some kind of temporary stasis," Donna explained.

Biting at his lower lip, the bowtied Doctor shook his head in denial.

"Spaceman, say something. Other than 'what'." Donna paused to evaluate his face. He was looking at her like she had announced that she had decided to turn into a teapot. Maybe she should slap him. She sighed instead. "Please."

"How did this happen?"

"You remember how Dalek Caan manipulated our timelines so that we'd meet? The same thing happened with me and River; fate caused our paths to cross again. We became friends without knowing who the other was. So when she found out, she convinced me to built this thing she designed. She said she could bring my memories back. Wasn't even sure it would work. But there was a chance, and I was willing to take it if it meant being whole again. It was the most important thing in the world to me and I didn't know why." Donna idly adjusted the vortex manipulator on her wrist. She could feel the weight of the Doctor's stare, and couldn't quite bring herself to meet it.

" 'S not like I had much else to do. Rich and bored and unhappy. Why not build a doomsday device as a hobby? A lottery fortune can buy quite a bit of black market alien tech, so thanks for that! Anyway, River's machine was a conduit to transfer her imprint from the Library computer onto some of the formless regeneration energy that makes up the metacrisis. But it's not like your memories, she's sort of independently active- like it was when I was inside CAL. Just that my subconscious mind is the storage now." She shrugged and smiled encouragingly.

The Doctor scratched at his cheek. "You downloaded River. Into your brain. She's in there with you."

"Yep. Here," she said, pointing at her head. Donna's eyes began to radiate regeneration energy, amber swirling over her customary blue. "Weeelll... specifically c'est ici. The closest human equivalent to a Time Lord's psionic locus." Donna's finger traveled six centimetres southwest on the ginger globe of her skull. She flashed the same brilliant, cheeky grin she had given him the last time she was on the Tardis.

"Donna," he said slowly and carefully, as if speaking to a sleepwalker. "It doesn't seem to be holding up very well."

The redhead blinked and the DoctorDonna personality she was unintentionally channeling fell away again. Her brow furrowed slightly over eyes brimming with questions. The unexpected lapse in River's defense seemed to remind Donna of her precarious state- the metacrisis could kill her. Seconds later, her deliberately airy smile was back in place. A brave face for him. Because of him. The Doctor's gut twisted painfully.

"Yeah, this arrangement ain't exactly an ideal solution. Miss Noble's Hostel for the Temporally Displaced is full up," she said in a teasing tone. "But it's working for now, and that's what matters. When River saw the metacrisis energy from the inside, she said that-"

The Doctor interrupted, his voice quiet but intense. "Does she... talk to you?"

"Yeah, I can hear her sometimes. Bossy, never gives proper answers, inappropriately flirty during times of danger. Sound familiar?"

The Doctor leaned forward. "Hello River, can you access Donna's primary auditory cortex? Are you able to communicate through her?" His voice rose like he was speaking to someone across the room and not a ghost buried within a foreign brain. "I need to know more about the neural overlay pattern you used so that I can lift it out intact. I mean, I could guess at it but that might be... nevermind. Oh, right. This is the Doctor speaking! Thank you. Bye!"

"Oi! I'm not her bloomin' ansaphone, you prawn, so quit shoutin' in my face!"

Looking suitably abashed, he whispered cautiously, "Is she saying anything now?"

Donna sighed. "No, sorry. I think she's been busy using all of her willpower in corralling the metacrisis." Her stare lost focus in introspection. "Tho' it's not really like a voice when she does talk. More like thoughts that just come to me, like a stray memory or something, but they're not mine. It's all symbolic like in dreams."

"So the additional consciousness is fully manifest and at least partially tapped into the limbic system. Good, I can use that. Going to try to bypass um... you, sorry... and contact her telepathically."

The Doctor reached his right hand towards Donna's forehead.

"No!" Instantly, her own right arm snapped up to grab his wrist in an overhand grip, her thumb biting into the soft tissue between his thumb and index.

In one fluid motion she rotated her arm from shoulder level down to her side. His trapped wrist was forced to follow, wrenched across his body, twisting beyond its normal range of motion to the point where his elbow was locked. A tiny bit more torque and one or more of the Doctor's joints would break. Her other hand had a death grip on his right shoulder.

"Now, now, none of that," purred the redhead. There was something off about her voice.

The Time Lord tore his gaze from his ensnared limb to Donna's face. Her eyes were shining with golden regeneration energy once again.

"D- Donna?" The Doctor regarded her angled brows and tight smile. He had never seen this expression on his companion's face. Donna could be shouty and stroppy, but never aggressive. His green eyes widened in recognition. "River?"

A tug on his wrist propelled the overbalanced Doctor forward into a warm female body. Then she was kissing him.

"Hi, honey, I'm home." River Song's low, musical laugh emerged from Donna's throat as she appropriated his line. "I've been waiting a while to do that. Ok, either kiss you or slap you. And I won't tell you Donna's vote on the matter." She winked a glowing eye and released his wrist.

"How is this... She was never... There's no..." The Doctor steadied himself against the Tardis console, thankful for something solid and familiar.

"I'm going to have to insist that you stay out of Donna's mind," said River pointedly. "You need to trust that I have this under control. The regeneration energy is contained for now, but it's a delicate balance. You're not barging in during a fit of reactionary heroics."

"I don't do that! My heroics are extremely helpful and, and... well-reasoned!"

Seeing the hurt look on his face, River was quick to offer a distraction. "The overlay I used was patterned based on Gallifrey Matrix schematic 445/Omicron. Modified for Human Plus but still stable. It will be fine. But I can't be at the surface long, so I'm going to trust you to let me handle this."

The Doctor nodded numbly and the golden light began to fade from the woman's eyes. "Wait, don't go yet!"

"What is it, sweetie?"

"You died. And I saw it and I could never say anything. To you or to your parents. I tried everything though, after it happened. Please believe that I tried... I've done all the maths, ran countless simulations. But I couldn't save you any more than I could save Donna." The Doctor ghosted his fingers along a lock of red hair, then pulled back his hand as if burned.

"I know," River replied gently.

"Darillium was... a while ago for me. And Donna, it's been so long since I had to leave her. Lifetimes. Not mine, but someone's. 316 years, 4 months, and 23 days in my personal timeline. Well, that's counting you both separately but I think I've earned the right to mark time however I please, haven't I?" the Doctor asked, his eyes downcast.

"And you've been carrying the guilt ever since."

"Of course. Regret is a major component of the missing-and-remembering package."

River took his hand and wove her fingers through his. "I have just the thing for that."

"What?"

"Today you help free us," she said with a feigned carelessness.

"But I- oh!" He grinned and tapped her nose. "You bad, bad girl. A Gallifreyan matrix overlay? Those can be extricated undamaged if you reverse it along the same pathways exactly." The Doctor dashed over to the console and began to noisily clack away at the typewriter.

"No, Doctor, just assist Donna. She can tell you the plan. There's work to do right now, plenty of time to talk later. I have to return to the subconscious before the metacrisis gains more ground. A girl could get used to this body, but I'm afraid it's only a loan." River ran her hands down her host's curves. The golden light was replaced with Donna's blue irises.

"Oi, that is your last warning about hands, Timehead!" Donna shouted indignantly at the ceiling.

The Doctor failed to stifle a giggle.

Not having a proper target for her ire, Donna shot a blame-laced glare at the Doctor. He opened his mouth to protest, but quickly shut it upon remembering the kiss. With his wife. Using Donna's lips. Those lips were currently pressed into an thin, angry line as she stomped toward him like a ginger juggernaut. Apparently Donna could remember the kiss as well.

No point running; the Tardis would just lead her right to him. His hands flitted about nervously as he tried to think of a way to placate her. "Your lip gloss tastes nice?"

Donna mouth formed an O as she made a scandalized squeak. She closed in on him. The Doctor wondered if any Time Lords had ever been slapped into their next regeneration.

"Strawberry, is it?" he ventured. "Better than anchovy like the last time you kissed me."

The force of her palm against his cheek made the Doctor whirl around in almost a full circle as his boots slipped on the glassy floor. The Time Lord rubbed at his aching jaw. "Blimey! You're even better at that than before. You don't practice slapping do you?"

"Course not. Naturally talented." Temper subdued, Donna now favored the Doctor with a winning smile. "I believe my counterpart said to get to work."


TBC