After reading Ruhaani's letter Sam left the bunker. He wanted to be alone, he had lost his love once again. But he could not catch a break hunts after hunts coming up, Dagon had Kelly who was carrying Lucifer's child and all man power was up against finding her and then after Cas killed Dagon with the help of Lucifer's child, he vanished, leaving them in the dark.
Then there was strange deaths of several hunters that kept them on their toes. After finding that Brits were behind all this and almost escaping death in bunker, they blew up Brits operation in States.
Lucifer's kid was born, Crowley killed himself in the alternate universe to give Winchesters a chance against Lucifer.
Cas died in front of Dean and Sam. He was killed by Lucifer and then they saw their mother being dragged away to another universe with Lucifer.
In a matter of few days Winchesters lost everything. On the other hand Ruhaani was trying to cure all the supernatural creatures. She didn't have a clue about what had happened in the States. She missed her boys. But she did have Gabe by her side.
"Gabe"
"Yes kiddo?"
"I want to go and see Sam and Dean and Cas"
"As you say Princess, anyway our work here is completed"
Ruhaani was zapped back to the bunker, where she saw mess all around, Gabe left her there to go check in heaven.
She walked down the stairs to find Dean, intoxicated by alcohol and Sam no where in sight. He must be in his room.
"Dean" Ruhaani called.
Dean looked up, his eyes filled with a distant thought, sadness and remorse. "Why are you here?" he asked in his hoarse voice.
"I came to meet you silly, I missed you" moving closer to him.
"Where were you when Dagon took Kelly or when all hunters were dying or when Brits tried to kill us or when Lucifer got free or when he killed Cas or when my mother was taken away from us?"
"Dean... Oh my god!" you tried placing your hand over his shoulder to offer him some comfort but he backed up.
"Don't you dare touch me, you abandoned me, you abandoned Sam" he shouted.
Sam came into the library, he looked worse than his brother. He ran straight into Ruhaani's arms, trying to find some solace in her arms. Ruhaani hugged him tightly.
He kissed her forehead. Ruhaani felt guilty, had she not left, none of this would have happened.
Her brother had died. Sam and Dean suffered torture in copious amounts and their family getting ripped apart from them had broken their hope and will.
After calming Sam and putting him to bed Ruhaani went looking for Dean, he was still drinking away his pain. Ruhaani took it away from him. He didn't say anything. Ruhaani picked him up and took him to his room, gently putting him on his bed and singing him a lullaby to calm him down. Soon the bunker was quiet.
Ruhaani had so much work to do.