The new Head of House Tyrell meets with Ellaria Sand. Olenna desires revenge for the dead of her family. They are plotting together. Olenna disses the Sand Snakes.

Game of Thrones - Season 6 Episode 10 (FullHD)

The last time a Tyrell came to Dorne, he was assassinated.
100 red scorpions, was it? You have nothing to fear from us, Lady Olenna.
You murder your own prince, but you expect me to trust you? We invited you to Dorne because we needed your help.
You came to Dorne because you needed our help.
What is your name again? Barbaro? - Obara.
Obara.
You look like an angry little boy.
Don't presume to tell me what I need.
Forgive my sister.
What she lacks in diplomacy, she makes-- Do shut up, dear.
Anything from you? No? Good.
Let the grown women speak.
The Lannisters have declared war on House Tyrell.
They have declared war on Dorne.
We must be allies now if we wish to survive.
Cersei stole the future from me.
She killed my son.
She killed my grandson.
She killed my granddaughter.
Survival is not what I'm after now.
You're absolutely right.
I chose the wrong words.
It is not survival I offer.
It is your heart's desire.
And what is my heart's desire? Vengeance.
Justice.
Fire and blood.