Here's where we find out what caused the change to Jack ...

"Tosh, why don't you tell them what we found." Gwen spoke and obviously had taken charge of the meeting. I wondered if this was the tension I felt, could Jack be resenting it? I couldn't think why as she often led discussions and he hadn't minded then.

Tosh cleared her throat. "The CCTV footage is not very clear. I've been able to isolate only one image, this one." The screen showed a blurred humanoid shape. "I had to filter out the glare and that's affected the quality of the picture. However, we've identified it as a Zenotope."

"Ah," said Jack, leaning back in his chair. It appeared to make sense to him.

"A what?" asked Owen, peering at the screen. I was glad he'd asked as I had no idea what it was either.

"A Zenotope. Torchwood encountered one in 1964. Very little is known about them but they radiate a form of energy when distressed and this has strange effects." Toshiko brought up another picture, of a dead, almost desiccated, cat. "This cat was struck by the energy in 1964 and was aged so much it died." Two further pictures appeared, of a child and a man, shown side by side. "At the same time this child was exposed to the energy and aged 30 years instantly."

We all looked at Jack. There seemed little doubt that he had been affected by the same thing but in reverse and by a larger degree; if he had been changed by 30 years either way it wouldn't have been noticeable given his unique physiology. He seemed lost in thought, not aware of our scrutiny which I thought odd.

"What happened to him?" I asked, nodding at the picture on the screen.

"He stayed like that. It was irreversible." Toshiko looked embarrassed.

"It drove him mad," said Jack, after a silence, "and he committed suicide. His name was Colin Baxter."

We looked at one another, not quite knowing what to say next. False reassurances would be useless. It was Gwen who found the right words and the right tone. For that alone I was glad I'd called her in.

"That was over 40 years ago. And, from the records, it shows he had a child's mind in a man's body. Very different to your situation, Jack. We have a lot more knowledge and equipment now. We'll find a way to reverse this." She sounded so positive I for one was reassured and I think the others were too. "Jack, do you know any more about these creatures?"

He sat up straighter, arms resting on the table. "Not much. I think there was another encounter with them, before 1964. Maybe in the 40s, I seem to remember it being wartime which was why there wasn't a detailed investigation. The energy was analysed though."

"Then that's where you start, Owen. Find the documentation and see what you can make of it. Ianto, give him a hand if he needs it. Tosh, will the Hub scans give us any more info?" I knew she was referring to the constant monitoring scans which operated throughout the Hub.

Toshiko nodded, "They could. I'll get onto those."

"I'd like to run another couple of tests on Jack. Now I have more idea of what I'm looking for there may be some residual energy I can trace," said Owen.

"Good, do that."

"What about the .. Zeno thingy?" I asked. "Should we be looking for it?"

"They don't hang around," replied Jack. "Once they've affected someone or something they disappear."

Gwen nodded, "Good. We haven't got time to hunt it down. Let's get started." She turned to Jack. "We'll have this sorted in no time," she said confidently and left the room closely followed by Toshiko and Owen.

Jack stayed where he was and I lingered. "Are you okay?" I asked. He didn't look it. He looked uncertain and ill at ease.

"I remember Colin," he said, nodding towards the screen where his picture was still showing. "He was kept in the vaults for a while before being transferred to a secure care home. I used to talk to him, tell him stories about space travel." He sighed then looked up at me. "If they can't fix this, fix me, maybe I'll end up like he did."

"No, you won't. Like Gwen said, this is different. You're an adult in a child's body with more knowledge and experience than the rest of us put together. There's no danger of you losing your mind." I put my hand over his. "And you've got us."

"Yeah, you're right." He smiled and squeezed my hand. "I'd better go and submit to Owen's tender mercies again," he scowled, pushing back the chair. We walked back to the work area. It seemed natural somehow to hold his hand; I think it helped both of us.

Poor Jack, not as confident as you might expect. Reviews always appreciated.