"The lowest, blackest and farthest from Heaven. Well do I know the way." – Virgil
They arrived at the edge of a lake. Dean looked around, waiting for another God or Goddess to appear when he saw Lucifer himself sitting on a rock waiting for them. Dean looked back at Tessa and she nodded as she started walking in Lucifer's direction.
As they approached Lucifer, Tessa told Dean he was now going to face his final challenges, four of them. If he passed all four, he would be able to go home, and all the souls would be safe. Dean nodded, ready to fight whatever Lucifer threw at him.
Once in front of Lucifer, he saw the man smile. Dean hated him for all he did to Sam but stood by without giving any indication to Lucifer of what was going through his mind. Lucifer looked Dean over up and down, before smirking and snapping his fingers.
In front of Dean appeared a version of himself. Dean was surprised but didn't let it show. The man in front of him started going over how he allowed Gadreel to take over Sam's body and all the things he did while in him, such as killing Kevin.
It took Dean a moment to fully realize what he was supposed to do, but once he did, he knew that he was going home. Looking his other version in the eyes, he forgave him for allowing Gadreel to possess Sam, sounding as sincere as he possible could. Dean saw the man flicker for a second before disappearing.
Dean looked back at Tessa, who simply nodded at him. "One down, three to go.", he thought just as a new version of him appeared. This time it was the Dean that made the forgeries. The new man started talking about all the times he had forged a badge or an i.d., and all the law enforcement agents he had lied to.
Yet again, Dean looked the man in the eyes and forgave him for betraying his country. The man again flickered in front of him and disappeared. Dean could tell Lucifer wasn't happy. He was sure that Dean would falter here, not being able to forgive himself for the things he had done, but seeing Dean so sincerely forgiving his other versions, was making him think that maybe he was able to actually pass the challenges and that didn't sit well with him. Although, he was almost certain that the next challenge would be hard, and Lucifer couldn't help the smirk that appeared on his lips.
In front of Dean stood a new version. This time was the Dean that almost killed Castiel while under the influence of the Mark. Dean took a deep breath, while hearing him describe each blow and hit that Castiel had received at his hands. Dean shook his head and gathered his thoughts, before looking the man in the eyes and forgiving him.
Dean could hear the huff of frustration coming from Lucifer as he watched the man in front of him flicker and disappear. "One more to go. Just one more.", he thought as he took a deep breath in and out, getting himself ready for the last one.
Just as Dean was thinking about it, the last version of himself appeared. This one was the one that wanted to kill God. For the first time since being in that circle, Dean faltered. How could he forgive himself for something he wanted to do for the sake of everyone on the planet?
Still, Dean looked him straight in the eyes while the man went on and on about all the things that would go wrong with his plan, and about all the people who would die because of it, before forgiving him for wanting to kill God. Again, the man flickered and disappeared.
Dean could tell Lucifer wasn't happy that Dean had been able to pass the challenges, as it clearly showed on his face and posture. Dean walked back to Tessa and waited for Lucifer to say something. He knew Lucifer could very well just keep him in Hell and not be bothered at all by it, so Dean was hoping that for once in his life he would do the right thing and honor the deal.
Lucifer got up from the rock he had been sitting the entire time and walked over to Dean and Tessa, telling Dean he had passed the final challenges by showing forgiveness and he could go home, before walking away and disappearing.
Dean looked at Tessa, waiting for confirmation that Lucifer was telling the truth and there was no hidden agenda. Tessa smiled at him, before kissing him goodbye and placing her hand on his chest.
Dean smiled back at her and suddenly felt a warmth spread from his chest, where Tessa's hand was still placed, to his whole body. He closed his eyes and allowed the warmth take control. "I'm going home.", he thought just before he disappeared.