We jump into this episode at the point where Megatron has just delivered his speech to the angels at the headquarters of Castiel's army:

Hannah looked doubtfully at Cas:
"I want to believe you, but I," she looked around at the gathered angels, "...we need proof. "

Without hesitation, Cas replied: "Name it."
Hannah nodded at Dean: "Punish him."
"Wha'?" Dean said, startled.
"He murdered Tessa. He broke our rules."
Lifting a hand, Dean started walking away saying:
"Y'all can all go to hell."
But before he managed more than a couple of steps, angels grabbed him, holding him back.
Sam exclaimed "Hey, wait a sec…" and instinctively tried to aid his brother but was also quickly held back by the angry angels.

Hannah continued: "You gave us order, Castiel, and we gave you our trust. Don't lose it over one man." She handed an angel blade to Cas. "This is justice."

Cas took the blade and held it, as he thought about everything that was happening. Dean stared at him in shock, until Cas shook his head and said: "No, I can't."

Hannah sighed and said something in Enochian. Cas answered heatedly, a few other angels also broke into the argument. Some of the angels started dragging the two brothers through the room, down the stairs and into a large windowless basement room.

Sam was hauled to the side, four angels still keeping a tight hold on him, while Dean was propelled into the middle of the room.

Hannah faced him haughtily:
"You have broken our rules and must be punished. Since Castiel refuses to do the right thing, we will do it for him. You will be allowed to live as a concession to Castiel, and when the punishment he and I have decided upon is completed, we will leave peacefully, as we can no longer accept the leadership of Castiel."

Dean ignored Hannah to stare at Cas:
"Cas, what the Hell? Are you letting them do this?"

Cas looked at Dean with sadness: "You did break the rules and Tessa is dead as a result."
"Come on, Cas: When have we *ever* followed anybody else's rules? Ever?"

Hannah continued over Deans agitated interruption:
"The sentence is reduced from death to flagellation, shoulder to knee."

"I'm sorry, Dean." Cas said, as Dean looked over at Sam, who'd gone ghost white:
"Sam? Flagel-what?"
"Whipping, Dean, they are going to whip you."

Sam was starting to struggle again, and more angels grabbed him, trying to hold him motionless.

Cas raised his voice:
"The agreement was strapping, Hannah. No broken skin, no permanent damage!"

Dean too was now struggling in earnest against the hands of the angels holding him.
"I thought you had my back. That is what family does," he spat at Cas, who could only answer: "I'm sorry. I couldn't spare you the pain or humiliation, I only managed to spare your life."

Two angels were trying to wrap leather bindings around Dean's wrists, as he twisted and kicked.

Hannah looked at him with something not far from disgust:
"This is going to happen. Why must you make it worse for yourself? Accept the inevitable with dignity and poise," she suggested.

Dean stiffened for a moment and glared at her:
"Screw you. Screw your bullshit dignity and poise. Screw that. Screw you. Screw all of you broken winged dickbags. If I go down, I'm going down loud and angry, and I am going to take as many of you assholes with me as I can. And that is a promise: I'll shred whatever feathers you have left."

And with that, the fight was on.
The two Winchester brothers fought in breathtaking synchrony, moving with such an easy grace and brutal elegance that it could break a heart to watch. It certainly broke Castiel's.
Sam went down first, flattened under a mass of angels, as they simply kept piling bodies on top of him until he couldn't move, while Dean was dragged, kicking and punching, step by step to where they wanted him.
Dean fought and struggled, but in the end there was too many of them and he ended up stretched on his toes, wrists tied to a beam running overhead, while rough hands undressed him.
He managed to kick one angel in the groin and another in the head as pegs were hurriedly hammered into the floor; before they managed to anchor his legs to the pegs with leather straps rendering him completely immobile in his bonds.

Hannah, who had slipped out during the fight, walked back in holding a heavy, broad strap of leather about as long as a man's arm.
She held it out to Cas, who shook his head and stepped back.
In the end, a burly male angel walked over to grab the strap and take his position behind the helpless naked man.

Dean had gone pale at the sight of the punishment strap, but now he straightened up, lifting his head.
Sam, who'd been trussed like a pig, looked on from his position on the floor as his older brother gathered his courage, embodying a bravery of defiance so noble and so hopeless that Sam had to close his eyes - it just hurt too much to watch.

Dean looked around at the angels.
"Screw you," he said.
Then he looked straight into Cas' eyes:
"Screw all of you."
Then the strap fell for the first time and he didn't have enough breath to use for words.

The angels watched.
They watched the strap rise and fall.
They watched a warrior's scarred body get pounded by heavy leather, not breaking the skin, as it had been agreed upon, but pounding muscles and the bones under them, bruising, deep purple blemishes painted on a body that had already endured so much.
They saw a brave man struggle against the pain.
They saw a man who had been tortured before and who just wouldn't break, a man, who refused to give them that, to give them anything, unless they took it by force.
A man who was silent under the assault, except for the grunts when air was knocked from his lungs, except when he now and again found the strength to lift his head and wheeze: "Screw you."
In the end, he slumped in the straps holding him, and the last of the punishment was meted out against a body, who no longer had a consciousness to know its abuse.

Any triumph the angels had felt was long faded at that time.
The victory, if there was any victory to be found, was, at best, a cold and broken victory, and they left the building in silence.

Cas had untied Sam, and together they had lowered the broken body to the concrete floor.
The tired, dejected, rejected, angel was holding out a hand to use some of the precious energy, he had left in his stolen grace to heal the man, he no longer was sure, he dared to call his friend, when Dean opened his eyes.
He woke by pure willpower, reached a hand through the fog of pain and grabbed a rough hold on consciousness, dragging himself into the light. Slowly he lifted his head.
Green eyes met blue eyes and Cas had the front row seats, watching helplessly, as the last vestiges of a man's faith crumbled and died on a cold basement floor. He closed his eyes, put a finger on Deans forehead and sent as much power as he could into the body, healing the muscles, the skin, there was a few cracked ribs too, from the struggle or from the strap, he would never know, but he healed them, healed it all, and wished he could heal more than the body, knowing that he couldn't.

During the quiet, silent, exhausted drive home, Sam turned the radio on. Dean let him, zoned out in his driving. In the darkness Jeff Buckley's lyric tenor drifted through the car:

"Maybe there's a God above
But all I've ever learned from love
Was how to shoot somebody who outdrew ya
And it's not a cry that you hear at night
It's not somebody who's seen the light
It's a cold and it's a broken Hallelujah…
Halle…."

Dean reached out, without looking away from the road, and turned the radio off. Sam didn't comment.

When they entered the bunker, Sam asked Dean if they were going to talk about all that had just happened. But Den was wrapped up in his own head, not in the mood for either explaining or for apologizing for bringing the first blade into the situation in the first place:
"Oh, I'm not apologizing. I'm telling you how it's gonna be."
Sam tried again, desperate to make his brother understand:
"Dean, that Blade…"
To which Dean simply responded:
"That Blade's the only thing that can kill Metatron, and I am the only one who can use it...so from here on out, I'm calling the shots. Capisce? Look, until I jam that Blade through that douchebag's heart, we are not a team. This is a dictatorship. Now, you don't have to like it, but that's how it's gonna be. "

Sam turned and stalked away to his own room.