They were taking Ianto back to the house. The Doctor had applied patches to monitor brain waves and the plan was that they were going to try and coax the aliens back inside Ianto's brain and use him as a temporary holding cell. Sort of like a police box. The Doctor couldn't help but smile at the irony.

Jack was slightly dubious; obviously worried that he would have his lover snatched from him mere hours after they'd made up. Judging by the way Ianto was keeping his distance, the Doctor had the feeling he was trying to soften the blow, just in case anything went wrong.

It was possible. The Doctor had been wrong before. But he was hoping with the strength of the TARDIS protecting Ianto's mind from actual invasion it would be alright.

Once again they snuck past the police tape and all the officers standing guard over the house and wandered into the hallway, heading for the front room.

"Right," the Doctor made them pause just outside. "I need you to do exactly what you did last time. Don't hesitate on any of the details and don't panic is something happens."

Ianto nodded and pushed open the old wooden door with one hand. Jack caught his wrist before he could move into the room though. Ianto glanced back at him.

"I'll be fine," he said, before Jack had a chance to open his mouth. "Trust me."

The look on Ianto's face was enough to make Jack relent. Of course he trusted him. He'd trust Ianto with his life. Well… figuratively speaking.

"Good luck," he said quietly.

Ianto nodded and wandered into the room. The writing on the wall didn't appear straight away, as though whatever caused it had sensed there was something different this time.

But as Ianto took a few more steps forward, the words shimmered into existence. Looking back momentarily at Jack and the Doctor who were stood in the doorway watching him intently, he began to read the writing.

This time he didn't feel weak, the world didn't shimmer out of existence and he didn't collapse. He felt like someone had poured water over him. He could feel it slowly dripping down his back making his spine tingle.

He shivered. The writing disappeared to be replaced by a slight blue tint to the world. Ianto shook his head a few times.

"Ianto?" The voice sounded like it was talking to him through water. He turned and caught sight of Jack. He looked at him with concern. "Doctor, has something gone wrong?"

The Doctor stepped forward and examined Ianto closely.

"No, I think we've managed to trap the alien in question," the Doctor grinned. "Easier than expected! Let's get him back to the TARDIS and I can find somewhere to store said alien whilst I run a few tests."

Ianto was still shaking his head, as though trying to dislodge water.

"Hey," Jack caught his arm. "It's alright. We're done now."

Ianto looked at him and nodded.

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Back at the TARDIS the Doctor managed to extract the alien from Ianto's brain, with a little help from the time ship herself, and apart from a headache Ianto was fine.

"I would give you some aspirin, but I don't keep the stuff on board," the Doctor said apologetically. "Allergies…"

He began muttering to himself as he waited for the TARDIS to return the alien to its physical form in a small see through container in the med bay.

"Ahh!" The Doctor cried as the TARDIS beeped.

"What?" Jack asked worriedly.

"It's a child!" The Doctor grinned at him, evidently pleased with his find.

"Of course it is…" Jack said absolutely no clue as to what the Doctor was on about. The Doctor rolled his eyes in exasperation.

"You remember I told you about the Isolus and how it stole all the children because it was lonely?" He asked. Jack nodded. "Well this alien - Damentin - lives entirely in make believe worlds. It feeds off the imagination of other species. In fact, quite a few of them live on Earth and present themselves in the form of imaginary friends. Obviously, they can only be seen by those with seven senses, so when the child no longer needs the friend they grow up and lose the sense, hence no adults know about them."

"Oh…" Jack understood.

"It was taking people because it was lonely," the Doctor continued. "You see, it must've drifted towards Cardiff and been sucked into the space temporal rift that runs through that house. Well it couldn't escape the rift, so it couldn't leave the house and it must've got so lonely that children started getting curious, sensing that it was sad."

"So that was why they were all attracted there," Jack replied.

"Exactly! But the rift stopped the Damentin from being visible to the children, because their seventh sense wasn't strong enough, so it had to suck them into it's imaginary world using the incantation written on the wall that only the impressionables can see," the Doctor finished, pushing his glasses up his nose and looking very pleased with himself. He put his hands on his hips.

"Well done," Jack smiled trying to sound enthusiastic but the fact that Ianto was safe was all that mattered.

"Oh sound a bit enthusiastic why don't you," the Doctor joked, grinning to show that he didn't really mind.

"Sorry," Jack wandered over to him, talking quietly. "Thank you."

"S'alright," the Doctor replied just as softly. "Ianto's probably not gonna feel very well for the next few days."

"That's ok," Jack nodded. "I'll look after him."

"Need dropping off somewhere?" The Doctor asked.

"The Plass," Jack said finally. "I'd better explain to the team what happened to me before I take Ianto home."

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The Doctor dropped Jack and Ianto off on the Plass exactly one hour after Jack and the Doctor had left in search of Ianto.

"I guess…" The Doctor shuffled his feet awkwardly as he stood in the doorway of the TARDIS.

"Yeah…" Jack nodded.

Ianto was stood a few feet away giving them time to say their goodbyes.

"Tell Martha I said bye," Jack continued finally.

"Will do," the Doctor replied.

Jack smiled slightly and pulled the Doctor in for a hug.

"Come back and visit sometime," he said quietly.

The Doctor looked down at his feet as soon as Jack had let him go.

"Yeah… about that…" the Doctor scratched his neck awkwardly.

"Just… if you're in the area…" Jack said knowing the Doctor had a bit of an aversion for the Hub. "Or drop by Ianto's place… I'll probably…"

He paused.

"Well, Ianto will let me know if he has a wandering Time Lord turn up on his doorstep," Jack cleared his throat.

"I'll come back next week," the Doctor said. "Well… if I say aim for next week then you'll see me sometime in the next few months probably."

Jack grinned.

"Bye Doctor," he said, waving as the Doctor disappeared back inside the TARDIS.

As soon as the time ship had disappeared from view, Jack turned and took Ianto's hand.

"Come on," he said. "I think I've got some explaining to do."