There's something almost profound, and simultaneously viscerally terrifying in the woman's words. Something in him focuses on we're not castes and echoes that over and over until it feels like his head is pounding with it, and when he opens his mouth to question what he means his voice sticks in his throat. Why is he trying to sing? He hates singing. He's never happy enough to sing and he hasn't been in years.

....Wait, what?

Sasuke physically shakes his head, wondering where the hell all that came from (and what it all means) when Elizabeth herself begins to sing. Something goes cold in his chest and if he didn't feel a little crazy before, he sure as hell does now.

"What are you doing?"

He doesn't mean just the song. It feels like she's reaching inside his head and shaking something.