After Naomi found Castiel in Dean's heaven, she took him and had him executed immediately. Before Castiel's actual death, he sent a present wrapped in green to Dean in his heaven. Dean was watching The Maze Runner with Sam, Gabriel, and Castiel when he saw something above the TV set. He got up then opened it. Inside was a piece of paper and a necklace with a trenchcoat and angel wings. Dean read the letter. It was about how Castiel saved him, why he wasn't able to see colors, their time together, and after Castiel was caught. Dean teared up looked at the necklace. He knew Castiel for a very short time but he didn't know that Castiel loved him all this time. He loved him before he even met him. He still loved him even after he forgot all about him and married another person. He looked at the Castiel that was sitting on the couch. He wasn't real but the real Castiel is dead and he resembled him. Dean rewatched all his favorite memories, Castiel was in all of them. When he first cooked with Sam, Castiel stood by them, making sure they didn't burn down the house. When Dean went to school for the first time without colors, Castiel was there, he made sure that Dean got through the day. When Dean got married, Castiel was watching from above. Castiel was in every single memory. Dean clutched the necklace tight.
"Cas." He had a broken grin as he walked towards the imaginary Castiel and touched him. He showed no reaction and continued to do what he was doing in the memory.
The heaven changed and Dean walked towards the hospital bed he was in when he was twelve. He sat on the bed and saw Castiel smiling in the corner of the room.
"Thank you, Cas." Dean smiled back at him and laid on the bed. He closed his eyes and thought of his blue eyed savior.