Dean blinked. He must have passed out. He tried to remember the last time he was conscious but all he could think about was black eyes. Lots of them. Working for Abaddon. He tried to move his body but it ached so badly he just wanted to lie where he was for ever and not have to worry. Wait….where was he?

Dean blinked again, this time he could make out the outline of a fuzzy room. He looked round and realised he was on an old sofa, in, what looked like an abandoned house. He saw Sam. Sam! He was okay, thank god. So, what happened?

He was starting to remember and the appearance of a certain trenchcoated man confirmed his recollection. Sam and Dean had been tracking down a group of demons who were working for Abaddon so they could find her. Thinking about it now, Dean wondered why they bothered. They didn't have the first blade yet as Crowley's people were still searching for it. So why did they go after a bunch of demons without any long-term outcome? It was probably just the excitement of killing some sons of bitches, Dean thought. He could tell that both him and Sam were becoming bored of the same silent research and awkward conversations about who should go for the beer run. Dean hated it, he knew he had done the right thing by his brother. Why was Sam so against his own well-being?

Focusing, Dean back-tracked, concentrating on the events of the hunt. He remembered taking out two demons but then something happened. That was it. A pain...all over his body. It was weird and it felt like it was radiating from his forearm. The mark. Damn! That must have been what had made him pass out. The last thing he recalled was collapsing on the floor of the demon's warehouse before spotting Cas appearing in front of him, angel blade at the ready.

Before Dean could even move anymore he was interrupted by a voice which could have belonged to a worried child's.

'Dean!' Sam rushed to Dean's side from where he sat on a wooden chair. Castiel, who was standing, also came and stood by the sofa looking over the brothers with care.

'You okay' Sam continued. Dean moaned as he realised his eyes were only half open and his body was coated in sweat. Wow, he must have been more messed up than he thought. He tried to convey that he was okay but nothing came out of his mouth but more moans.

It took him a couple of minutes to get his head straight and to prop himself up on the sofa and Sam's worried comments didn't help. When he was finally stable did Castiel start throwing concerns.

'Dean, that mark-'

'Yeah, I know. Mark of Cain, pretty peachy apparently' Dean replied with a sarcastic tone as he took a gulp of the bottle of water that Sam had handed him. His mouth still felt dry even with this gulp but that was the least of his problems.

'Dean!' Castiel's harsh, loud voice rang through the old house. It made Sam jump and forced Dean to look up into those blue eyes as the angel continued. 'You don't understand! Bearing that mark is dangerous. Elders used to say even the mere mention of it could wipe out masses of angels.'

'Well, you're still here'

'It's not funny, Dean! Can't you see what it's doing to you?'

Dean looked over to Sam to judge the severity of the situation and it wasn't good. Sam looked broken and troubled, kind of like he used to look before Dean had made the conversations awkward. All eyes were on Dean as he attempted to sooth the concerned expressions in the room.

'Look...I hit a rough patch, that's all'

'How can you say that? Look at you, Dean?' Sam attacked back, whilst gesturing at Dean's weak body.

'Has this happened before?' Cas demanded.

'What? No!' Dean could tell he was losing the crowd but he honestly felt better now and just wanted to forget about it. 'I'm fine.' Sam gave a small laugh as he turned away from the group, looking towards the broken window at the side of the house. 'Look, this weapon or mark or whatever this thing is, yeah, it sucks...but it's also the only way of killing Abaddon. I mean, that's got to be the main priority here. Come on!'

'You have no idea what it's doing to you' Castiel retorted back with an air of superiority in his voice.

'Yeah and I don't really wanna know, so can we keep it like that'

'You should never have agreed to take the burden, Dean' Cas seemed genuinely upset at this point and it reminded Dean of the angel's time as a human and exactly how much effect it had had on him but nonetheless Dean argued back.

'And I suppose you have a much easier and better way of getting rid of Abaddon!?'

Castiel was stumped as all three of the men knew there was no other option with the knights of hell.

'Dean...the mark isn't just a weapon.' Cas began. 'It's an energy consumer. It feeds off the bearer like a parasite, collecting enough energy so it can use the first blade to kill demons. That's why you collapsed.'

Beginning to understand what they were dealing with, Sam interrupted Cas. 'You said Abaddon was at the demons hideout'

'Yes.' Cas replied. 'When you ran into those demons, quite recklessly I must say, the mark could sense Abaddon's power. It began draining energy from you, preparing to pick up the first blade and turn it into a deadly weapon. The amount of power being radiated from you, Dean, all angels on earth could feel it. I came as soon as I could but I was too late and you collapsed right in front of me'

Dean nodded but was more than confused. 'Cain seemed pretty perky to me when he had this print, and, I mean, he wore it for years before me. What makes him so special?'

Sam and Cas shared a look at Dean and for a second it felt like the old times. Dean hated the patronising looks after his stupid comments but he didn't half miss them.

'The mark wasn't meant for humans.' Cas answered. 'Demons can't be killed by the conventional means so they can afford to have their life sucked out of them...if they have any life left. Besides, Cain is the first demon...spiller of family blood, brutal murderer of thousands-'

'Okay, I get it' Dean answered back. 'Oh, and you might want to check that story you have of the dude because the guy seemed pretty stand-up when I met him'

There it was again, the shared look from his brother and friend, this time with a disappointed exhale of breath. Sam decided to take this one.

'Say again?'

Dean knew this would make for a great story and sat up a bit more to tell it. 'Yeah, it turns out, he didn't kill Abel because he was jealous. Cain made a deal with the devil in exchange for his brothers soul in heaven''

'That's impossible' Castiel replied instantly.

'Oh, I'm sorry, have you met the guy?'

'Dean, he's a demon' Sam agreed. 'He could just be lying-'

'Oh, whatever you guys want to believe but why would he give me this mark so that we could kill Abaddon?'

'The mark is draining you Dean.' Castiel replied. 'If anything, Cain is probably working with Abaddon. He trained her himself and she's his last knight of hell'

'Cain killed the knights of hell.' Dean stated honestly, waiting a moment for the news to kick in.

'What? No...the archangels killed them, why would he…?' Castiel now looked more confused than ever and couldn't quite comprehend the information being given to him.

'He's on our side, trust me. He wants demons as dead as we do. Now, instead of sitting around talking like girls we should go and find this bitch.'

Dean attempted to stand but he stumbled and would have fell to the floor if it wasn't for Sam lifting his weight.

'You're not going anywhere until you've rested up' Sam ordered, suddenly controlling the situation. Now that Dean had stood up he felt worse again and he could feel himself blacking out a second time. Sam must have sensed Dean's quick deterioration as he turned to a static Castiel. 'Can you teleport us somewhere safer...preferably with a bed'

Cas shook himself and laid a hand on each of the boy's shoulders ready to take them to the nearest motel. Dean felt his feet lift off the ground as he drifted into unconsciousness again.