Brienne loses count of the number of Frey men-at-arms who fall beneath her sword as she drags the screaming Catelyn Stark from the Red Wedding.
It isn't like Renly and the shadow; the Freys are just men, and Brienne can kill men.
She can save Lady Catelyn as she couldn't save Renly.
Lady Catelyn rages - at the Freys, at the Boltons - she tears at her hair.
Eventually she turns her anger on Brienne.
"Why didn't you save him? He was a king, he was my son. You should have left me and saved him."
Brienne thinks of the guards the Young Wolf had surrounded himself with - Dacey Mormont, Smalljon Umber, Wendel Manderly, others whose names Brienne had never learned - all fallen in defence of their king.
Brienne is not arrogant enough to believe her sword would have saved him when those others could not.
Anyway, she did not swear her sword to Robb Stark, she swore it to Lady Catelyn.
Catelyn weeps herself to sleep at night, and Brienne has no sweet words or gentle touches to offer her.
The only thing Brienne has to give is her strong sword arm, and that is already Catelyn's.
"I should not have let Robb dissuade me from sending you South to exchange the Kingslayer for the girls," Catelyn says bitterly.
Brienne would never give voice to these thoughts, but she is glad that Catelyn did not send her from her side.
If she had been in King's Landing then who would have saved Lady Catelyn from the knives of the treacherous Freys?
It surprises Brienne that the Freys haven't sent riders after them.
Perhaps after the massacre at the Twins, because a massacre is what it was--
A massacre that I fled from, thinks Brienne, like a craven.
I had to, she thinks, it was the only way to save Lady Catelyn.
--Perhaps they are yet to discover that Catelyn's body was not among the slain.
They sleep under trees and beneath hedges, Brienne lights a fire on nights she believes they can risk it, elsewise she gives Catelyn her cloak to sleep under.
There is something that may be the ghost of a shadow of a watery smile on Catelyn's face as Brienne frets about how this is utterly unsuitable for a highborn lady like Catelyn.
"You are highborn yourself, are you not?"
"Do you not sleep, Brienne?"
"I must keep watch, my lady. If riders come--"
"If they come, they come," says Lady Catelyn with weary resignation. "And you will be in no state to fight anyone if you do not get some sleep."
"Sleep, Brienne. Grief is a cold companion who keeps me awake at night, I will rouse you if I hear anyone approaching."
When Brienne wakes at dawn she is curled protectively around Catelyn, and her lady breathes deeply and evenly, sound asleep beneath Brienne's sheltering arm.
"Where shall we go, Brienne?" asks Lady Catelyn in that hollow voice that shatters Brienne's heart. "Winterfell is sacked and burned, and if Riverrun isn't in the hands of the Lannisters it will be soon enough."
Brienne hadn't realised it until Catelyn asked, but she has been unconsciously directing them towards the coast, to the only place she has ever felt truly safe and loved.
"To Tarth, my lady. Evenstar Hall, my father's seat--"
"No!" Brienne is shocked by the vehemence in Catelyn's tone. "I'm sure Lord Selwyn is a good man, Brienne--"
Selwyn of Tarth is the best man Brienne has ever known. He would be appalled at the treachery of the Freys, and he would shelter Lady Catelyn as his guest, he would honour the vows his daughter had made.
"As you are a good daughter. I would not have you bring such grief as this into your father's hall."
Lady Catelyn pauses, then, "White Harbor."
They risk taking shelter at an inn for a night. They are closing in on the White Knife and folk here are more likely to be sympathetic to fugitives from the Lannisters.
Still, they keep to their room - Brienne at least cuts a recognisible figure - and retire early.
Brienne has been told more than once that she has the hands of a man. Her old septa had meant it cruelly, her old master-at-arms kindly, hers were hands that could swing a sword through bone and sinew.
Brienne's hands were not made for gentle touches, and yet Lady Catelyn leans into Brienne's caresses and murmurs, "Ned, Ned..."
Everything I have to give is yours, thinks Brienne.
She presses her lips clumsily to Catelyn's neck. She can't see her red hair in the dark, but she can imagine it.
"Catelyn," she whispers.
"Cat. He always called me Cat."
"I would have died were it not for you, Brienne," is all Lady Catelyn ever says of it. "I would have gone mad, and died with Robb, and been glad of it."
"I-- My lady?"
"Thank you, Brienne."
"What will you do now, my lady?" Brienne asks once they've reached White Harbor.
"The same thing Lord Wyman will do. I'll bend the knee to the Lannisters and acknowledge Roose Bolton as Warden of the North, and hope that will be enough for them to return my living children to me. And I'll pray, Brienne, I'll pray that wherever they are Ned and Robb can forgive me."
Wyman Manderly tells Brienne a story.
It is a strange tale, a tale of a mute Ironborn squire, two innocent peasant children brutally slaughtered, two small boys and two large wolves, and an island of cannibals.
"Will you go?" Lord Wyman asks.
"Yes," says Brienne, she doesn't have to think about it.
She has sworn her sword, has sworn everything she has to give to Lady Catelyn.
She cannot give her lady more children, but she can bring back those who have been falsely taken from her.
"Yes, I'll go."