Stiles doesn't even hear Peter's words, all he can hear is the gentle sweet musical words calling to him. Calling for him to join them.

"It's so beautiful," is all Stiles says, and not really so much in reply to Peter but because of the mermaid's song has enraptured him. They're calling to him, telling him to join them, it'll be so much fun. He belongs with them, they tell him.

The further up shore they get, the outlining of caves becomes visible, and Stiles is heading right for it. He stumbles over old debris from the sea but doesn't fall, doesn't falter.

He has to get to them, he has to follow.