Thank you for your kind reviews :) This story will have 5 chapters, and maybe a sequel on a character, but I'm not sure about this yet.
Three days passed without any sign of anyone else than the two of them. Ianto stayed silent and in a corner half of the time, then Jack talked him out because he needed to shower. Ianto showed him, silently, and he turned away to let him have some privacy. He gave him new clothes that Jack didn't know where were coming from but didn't ask, and Ianto cooked for him. He had noticed the kitchenette – though only accessible to Ianto – but didn't question it either. He assumed that whomever were keeping them here didn't come every day to give his meal to Ianto. After all, he had been here for a few years now, if he were a threat, they wouldn't have let him be so free – as long as one could be in a cell. Sometimes, it looked like he wasn't even their prisoner, but a strategy to make Jack talk. To make him confess where his friends were.
Except that Ianto never asked anything. Maybe that was a way of interrogation. But Jack didn't want to go all paranoid. And he really wanted to help Ianto. He could hear him at night. He could see he had nightmares and he really didn't want to know what he was dreaming about. It seemed horrible. He knew he would wake up at least twice in the night, screaming, and he didn't even seem to realise it. Jack was sure he would apologise to him the next day otherwise.
The first night, he hesitated to do something, but then Ianto woke up and calmed himself alone and went back to sleep. On the third night, Jack felt a presence at some point, next to him. Ianto came quietly and lied down against his back. Jack wanted to say something but he didn't and Ianto was gone when he woke up – well he was still in the cell of course, but away from him.
There was something else very odd. Every time they would touch, even just brushing fingers, Jack would feel weak. Really weak. He didn't know what it was, and he wasn't sure he wanted to know. He had heard love stories about that, but he didn't want to think about it because it seemed stupid to fall in love with someone in a cell. Even though Ianto was quite good looking, and Jack liked him, it wasn't the time nor the place.
From what they had talked about, Jack didn't learn a lot more. He learned that only one person ever succeeded to break the door but got killed right after. As much as Jack wanted to get out, he was afraid of dying because he knew his powers weren't working for now. He didn't know how, and every time he tried to ask Ianto, he would just avoid talking for hours. He had stopped asking aloud but he was thinking about a lot of possibilities and none seemed to be the right one.
The fourth day, Ianto was next to him, staring down at him, when he woke up. He was way too much in Jack's personal space, but it's not as if being cell mates didn't imply that, and Jack didn't joke about it because Ianto had a too serious face on. They looked at each other and Ianto took Jack's pillow in his hands.
"You have to do it," he eventually said.
"Do what?" Jack was still half asleep and even wildly awake, he wasn't sure he could have understood.
"You have to break your promise," Ianto continued with the same too serious tone.
"Which promise?"
"You said you wouldn't hurt me."
"And I won't! Ianto I'm going to help you, even if I have to die."
"Why?"
"Stop asking why. Because. That's what I do. I try and help people 'cause I don't know what to do with my powers. I'm invincible, I can't stay permanently dead, but others can. I have to protect them."
"But you don't have your powers any more," Ianto retorted, somehow desperately.
"I don't care. I'll find a way to get them back and I'll take you with me. Out of this nightmare."
"I'm offering you a way. Kill me."
"I'm not going to kill you, Ianto!"
"I know you can feel it! I can see it in your eyes! Every time we touch, you feel it."
Jack frowned, afraid of where this was going. How could Ianto have guessed?
Ianto grabbed his arm, strongly, and Jack felt it again. His body growing weaker and weaker. It was worse than any time before. A sudden pain tore his chest apart and he yelled. Ianto let go off of him and all the pain just disappeared. He had no physical injury but it had felt like someone had stabbed him.
"See? That's what I do," Ianto whispered, tears in his voice.
"What do you mean?" Jack asked, genuinely confused, or refusing to see what was standing in front of him.
"They didn't build anything to restrain your powers. They didn't have to. They just put me with one of you- one of us, when they're afraid."
"They're afraid of me? I can only heal myself..."
"No. Jack, you are much more powerful than you think. I can feel it, coming out of you. That's why you feel so weak around me. When I touch you."
"Ianto..."
"You know what this is. You guessed it. You just didn't want to face it. But you have to kill me, to save yourself."
"I can't!"
"What about your friends?"
"They'll do fine without me."
"Will they? I'm dangerous. They'll use me as a weapon one day. They won't keep me here forever. They'll use me, and you know it. They'll control whatever I can do. You know they will. You can't heal yourself because I'm here. I'm doing this to you! My power is to suppress others' powers. I try to repress it as much as I can but it's still suppressing your powers. What you felt... this is what it feels like if I don't contain myself. So please, kill me and save yourself."
"Don't ask me to do this..."
"Why?" Ianto asked, now angry.
"'Cause then I get to live with this! You're a human being, Ianto, I can't kill you!"
"This is selfish!"
"Killing you would be selfish too!"
"You'll save everyone, you know what they're going to do!"
"I can help you!"
"You can't. Please... Please..." Ianto cried, and Jack stilled. Was he begging him?
"You want to die..." It wasn't a question, more of a statement, but Ianto nodded anyway. "But why?"
Jack asked after a few seconds. Ianto shrugged and stepped back, letting go of the pillow and clenching his fists. Jack followed suit and got on his feet, facing Ianto.
"This isn't life. I'm a danger. I don't want to hurt people. I... I didn't want to die before. But I can't bare looking at you while knowing you're weak or in pain because of me."
"Why?"
"You've been so kind to me. They've all tried to kill me to escape. The one who didn't wouldn't talk to me. He understood right away, but he didn't kill me. He refused to talk to me, though. It's the one who opened the door. He's dead now. I don't want you to die," he admitted, looking away.
Jack was the one to step into his personal space this time. And Ianto didn't move but he didn't look at him either. He only stared in puzzlement at Jack when the man put his hands on his cheeks and smiled weakly.
"I told you, I won't break any promise I made. I will help you."
Ianto shook his head but Jack silenced him with a kiss. He hadn't really intended to kiss him on the lips, but Ianto was still shaking his head, so it just sort of happened. And he didn't pull back, nor did Ianto.
There was pain. Throbbing pain. As if his chest were burning – which he could tell by experience. It hurt like hell, but he didn't move. He concentrated on kissing that poor lost boy. He had no powers but he could still try and do as if he had. When Ianto relaxed under his hands and responded, the pain disappeared. He felt warm, but it didn't burn any more, and it felt rather good. He had already tried to give just a little sparkle of life with a kiss more than once before, he had saved some lives like that. That's what he tried to do this time as well, and it seemed to work, even if he couldn't feel his powers any more.
When they parted, Ianto tried to step back, but Jack tightened his arms around him and hold him tight against him. He couldn't feel the pain any more, he didn't feel weak any more. He could do this.
"I'm going to save you. I promise I will."
The fifth night, Jack was gone from the cell when Ianto woke up in the middle of the night. He had wanted to lie against Jack, because he actually managed to rest when Jack was here, but he was gone. Ianto wasn't able to go back to sleep and a day after, the door opened. Ianto thought they would put Jack back in with him, but instead they took him and Ianto didn't fight back. He had stopped years ago.