I knocked on Black Seven's door after I picked up the shot Harley gave me. But before I'd run some tests, I wanted to ask Jay if he knew anything about this liquid.

"It's open." His voice said and I opened the door, carefully looking over my shoulder to make sure Harley, whose room was just upstairs across the hall, didn't see me entering. I promised Black Seven to keep his presence here a secret from her because of some reason, he didn't want her to know he worked together with me. And I sure as hell didn't want my secret to cone out by letting my house become a little home to all kinds of crazy people.

"What up, B-Man?" Jay asked, laying on his back on the bed with his legs up the wall and playing some game on his phone. It was like having a twenty five - or something under thirty - year old teenager.

"What do you know about this?" I took his phone and handed him the shot instead, making his eyes change from annoyed and slightly angry to interested. Black Seven smiled and played with the shot as he looked up at me. "Well. Looks like a shot with a green liquid."

Far be it from me to lose my self control but Jay - more than everyone else I've ever known - got on my nerves. Even more than Bat-Mite. "A simple no would've worked as well." I took the shot from him and gave him his phone back.

"Who said I didn't know somethin' 'bout that? I know a thing or two." Black Seven stared at his cellphone and just kept playing that game. "But I see you really ain't in da mood for it an' neither am I."

I facepalmed so hard, I was sure Damian who sat in the batcave could've heard it. "You're right, I'm not in the mood. But this thing has been sent to Harley. Maybe I should tell her to take it. She might die then."

It didn't take even a heartbeat and Black Seven popped up right in front of my face and grabbed the shot right out of my hand. "Party pooper." He growled with a smile and pointed at a nearby chair. "Ya betta sit down. This might take a while."

Having no clue what he was talking about, I walked over to the revolving chair and looked at him in curiosity as stared at the green liquid.

"I can't tell ya the name of this...although I know it." His eyes had a weird twinkle and I narrowed my eyes, trying to figure out what he was on about.

"But I can tell ya a lil story about it. And what it has ta do with da Joker." Jay blinked as if he tried to get rid of an unpleasant thought. What was it that bothered him? 'Can't be anything good.' I figured, because there weren't lots of things that let him get serious.

"When Joker was some sorta part o' me, I helped him develop a view new chemicals for, what he called a bat-challenge. Guess he meant you by that." Jay's eyes were still locked on the shot but he finally managed to look at me while opening a drawer in his desk and searching for something.

'Bat-challenge?' What did the lunatic mean by that? And what kinds of chemicals? Paralytics? Some sort of Joker Venom? I was going crazy with questions but tried to focus on what Black Seven said.

"Later on, he had one other request. One that was a bit disturbing. And funny, though." Jay scratched his belly and opened up another drawer. "Since he had his body preserved by the Dollmaker but up ta forty percent of his internal organs were damaged to a point where regeneration was impossible and my body - somehow, don't ask because I don't know how either --" Black Seven finally got a screwdriver and looked at me.

"-started ta replace my cells with his, maybe 'cause of his blood I had in me, Joker asked me for help 'bout gettin' his body back to life. An' ta get 'im outta my mind, Dollmaker and I had ta get his body back." I gulped. Somehow, I started to feel bad for him. Having Joker around twenty-four-seven was already punishment enough. But an irgan donor while almost fully conscious - as Jay told me some time ago...that was some weird stuff.

"Anyway, I did it and Joker owed me a huge favor. I told him I would tell him when I would come up with something. Honestly, I wouldn't have thought I'd ever ask Joker for one." For a moment, Black Seven's eyes got a happy twinkle and he smiled in a whole different way than usually.

"But then da thing with Harley happened." He stared at the screwdriver and his smile faded as well as his happy look. "And soon as he was outta me, I didn't even have ta ask him for it. He just said he 'got the joke'. Didn't know what he meant by that. Till ya showed me this."

Some thought made its way through my mind. 'Is Black Seven really insane?' I thought, biting my lip by simply thinking about the possibility. 'Or is it Joker's blood that turned him into this?'

"But what does this liquid do?" I asked, knowing it would be just annoying to Jay if I actually tried to have a conversation with him that involved his feelings.

The crazy look returned and he put down the shot. "Just watch this. And don'tcha do a thing!" I didn't have a good feeling but I nodded. Couldn't be too bad...could it?

Black Seven grabbed the screw driver tighter while counting quietly, only moving his lips as he moved his fingers down his back. "There we are." He grinned and picked up the shot again.

"Y'see, I've been thinkin' 'bout paintin' ta whole room new." Jay walked back until he stood with his back against a wall, calmly looking down on his screwdriver while I tilted my head again, curious about what he was up to.

"White walls aren't my favorite ones." He walked forward exactly four steps and held the tip of the screwdriver against his back. It slowly occurred to me what he was trying to do but before I could react, he ran backwards against the wall. His vertebras made a cracking sound and Black Seven immediately fell down on the floor, making me jump up from the chair in shock.

"Jay, what the hell?" I yelled, already about to call Alfred over but Black Seven just grinned at me with glassy eyes. "Will you sit down?" He glared at me and I didn't know if I should listen to him.

"Are you insane?" I asked with big eyes and just received a grin from Black Seven as he pulled the screw driver out of his spine. "Yeah, but why ya askin' me this ova 'n' ova again?"

Blood and small pieces of bone on it, Jay threw the screwdriver aside and stuck the shot into the hole in his back, then kept smiling while scratching his head. "Looks like ya have trust issues, eh?"

"What?" I couldn't really pay attention to his words as I watched his legs twitching as if they were electrified. "Well. Trust has to be earned." I said as I finally looked at him.

Black Seven threw the shot aside and slowly turned over to his side. "I feel like you are scared ta trust people because ya don't wanna be disappointed. I actually don't want people to trust me because I don't wanna disappoint 'em." I just stared at Black Seven, surprised by this.

"It's bad when people have lying issues but, speakin' from experience, I'm gonna tell ya this." I gasped as Jay moved his legs and slowly stood up. 'That...liquid healed his broken spine?!'

His legs were shaking as he leaned against the desk before sitting down on it. "That will get better, Bruce. Ya just need ta stop blaming the people around ya for yer past."

It was clear he had problems to think straight, maybe because of the pain but I knew what he tried to say. "Thanks, Jay." I put my hand on his shoulder for a moment.

"Just tellin' ya this." I looked at him, yet again, confused and a little curious.

"Afta Nightwing is up for the role as the flying rodent, I'll be on ta dark side again." He must've noticed my disappointed and also a bit scared look because he put on a happy face, trying to cheer me up. "But don't ya worry, yer secrets are save with me. I promise."