"Maybe… maybe it is this sensory thing," Jack suggested as they began trying to figure out how the mental patients slotted into the Doctor's theory.

"I hope that's not the end of your thought," the Doctor said pulling his glasses off his nose and rubbing his face for the umpteenth time that hour.

"Maybe because they're mental patients, they never lost the ability for the last two senses to generate?" Jack was taking random shots in the dark and the Doctor had the feeling he was more in risk of decapitating himself than taking down the mystery alien.

"When did they develop their illnesses?" The Doctor decided he might as well check each shot before shooting it down though.

Jack leafed through the files.

"Fourteen, twenty three and forty," he sighed. "Bit late right?"

The Doctor nodded. Then reconsidered frowning. He pulled the files towards himself.

"Maybe not…" he looked them over. "They were all genetic. Which means the potential for the illness to develop was there from birth."

"Which means that even if it hadn't affected them, it might still have protected those seven parts of the brain, including the two we don't normally use?" Jack asked hopefully.

"Could be," the Doctor nodded. "Which… if I'm clever and well…"

He pulled a face that said 'who wouldn't call me clever?'.

"I can work out which species is doing this to them," he paused. "There's one problem though…"

Jack looked at him.

"What?" He said, not liking the tone of the Doctor's voice.

"Well… in order to confirm which species, and in order to save the others, I'm going to have to us one of the impressionable," the Doctor replied.

"You mean Ianto," Jack glanced down for a moment. "What do you need him to do?"

"Well first of all I need to cure him," the Doctor paused. "But… because I'm going to have to give it directly to his body, I'm gonna have to bypass the blood brain barrier and inject it straight into his spine, which not only risks haemorrhaging, but also strokes, or even partial brain damage."

"You're not really selling the idea to me Doctor," Jack said looking terrified at the thought of Ianto being brain damaged.

"Ok, let me put in a different way," the Doctor took a step towards Jack, lowering his voice and looking him straight in the eye. "We don't do this, Ianto stays a vegetable for the rest of his life, and even when his body dies, there's nothing to his mind won't live on. We cure him, there's at least an eighty percent chance he'll be completely fine and you two will live happily ever after."

"Doctor," Jack didn't sound convinced.

"Ok… seventy percent chance," the Doctor admitted. "Sixty five at the least."

Jack looked down at his feet, still not liking his options, but he knew he had no choice.

"Jack, trust me, if there were any other way," the Doctor watched him carefully.

"I know," Jack looked up finally. "Ok, let's do it."

The Doctor prepared everything while Jack had a few minutes with Ianto. He didn't think he'd be able to forgive himself if he hurt the Welshman in any way. Although, having said that, the pain he'd cause over the last four months was probably more than he'd like to think about.

"What happens if Ianto is brain damaged and can't help us?" Jack asked.

The Doctor looked up from where he was preparing the mixture and drawing it into a syringe. For a moment he looked like he was going to say something, and then he changed his mind. He wandered over to the bed.

"Turn him onto his side and tuck his knees up to his chin," he said to Jack instead.

Jack did as he was asked and watched as the Doctor prepared to inject the solution. He glanced at Jack for a moment.

"Whatever happens, you made the right call," he said quietly.

"I know," Jack nodded.

The Doctor injected the liquid.

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The last thing Ianto remembered was telling Jack something. But Jack had gone hadn't he? No… yes… but he'd come back. Ianto had been somewhere strange. Strange yet familiar. The TAR… TAR… oh what was it?

Ianto suddenly sat bolt upright. Everything he'd been trying to remember slowly slipping through his fingers. Like a dream you know you've had but just can't remember what about.

He was in his own bed, in his own flat and he could hear movement. Hang on… he hadn't been here before. He didn't remember going to bed here… he'd defiantly been somewhere else.

There was the sound of footsteps and Ianto's bedroom door opened. Jack Harkness stood there holding a tray with breakfast on it.

"Morning love," he said smiling as he wandered in. He was wearing a dressing gown and Ianto had the feeling there wasn't anything else underneath.

"Jack…" he said in slight confusion.

"Yeah, that's me," Jack chuckled, handing Ianto the tray and climbing into bed beside him.

"But you weren't here," Ianto frowned. "And I wasn't here."

"Course you were silly," Jack looked confused now. "And so was I. We live here, remember?"

Ianto looked at the tray he was holding for a moment.

"We live here?" He asked. "How long..?"

"About a year now," Jack reached out a hand to Ianto. "Are you ok? You don't look well."

Ianto felt it then. In the pit of his stomach. This wasn't real. It was only here because he wanted it so much. He pushed the tray away and wriggled out of bed, looking at Jack.

"You… you can't be here…" he said.

"Ianto, love, it's me," Jack was starting to sound upset. "What's wrong?"

"You can't!" Ianto almost shouted. He started heading for the door. But before he reached it the image flickered and shifted.

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Ianto sat bolt upright and almost knocked the Doctor and Jack flying. He stared at them for a moment as he let the memories flood back. The TARDIS, the house, the Doctor, leaving Torchwood, Jack, the missing children…

"Ianto?" Jack was there, in front of his again, reaching out to take his hand. "Are you ok?"

The Doctor was checking his vitals asking him questions that were flying straight over his head. All Ianto could see was Jack. All he'd ever been able to see was Jack.

"Don't ever leave me again, do you understand?" Ianto sobbed quietly as he pulled Jack into a hug.