[Dream] The Prophecy and The Hound

A prophecy says the Hound can only be killed on Valyrian soil. When he stops a caravan on its way to Highgarden and demands that the occupants come out, therefore, he thinks he is safe.

From inside the caravan, Ser Loras Tyrell fires two arrows. 

The first arrow merely pierces the wall and sprays the Hound with dust. 

The Hound looks at his already soiled cloak and realizes that this new dust is from Valyria.
"Oh, fffuck!" he says, more pissed off and disgusted than afraid, though he knows what is coming.

A second arrow pierces his armor and thumps into his chest.

He drops to his knees.

The ground drinks his blood.