Quentyn to presumably become ruler of Dorne, but she thinks it won't be enough. She learns from Arys that Tywin is dead. So that news has now reached Dorne. She thinks Cersei will be easier to deal with.
It is also made very clear (surprise surprise) that she's just using Arys. He might be all right in the sack but she thinks he is dim-witted.
All she has to do is reach Hellholt (sounds like a lovely place) and crown Myrcella. So obviously it goes wrong. They reach an appointed boat crossing and Areo Hotah is waiting. Arys tries to fight but gets his head chopped off. Arianne goes completely to pieces, which makes me wonder how effective at Queenmaking she could ever have been anyway. Myrcella is on the ground having a fit with her head in her hands and blood everywhere. I think she could be dead. That will probably get Cersei to attack the Dornish, which probably won't go well as it sounds like even the Targaryens had trouble with them thanks to the hot climate which is not conducive to fighting in armour.
Oh dear, what a mess.
