Promise is on her way from the library, where she has been allowed the privilege of an hour's study of sorcery - directed in topic, but she was allowed to take (relevant) notes, and read (relevant) books, and was only lightly supervised.

Thorn sometimes likes to butter her up, such as it is, before calling her to his room. She thinks he's running elaborate multivariable experiments on what puts her in a marginally more or less cooperative mood. The obvious confounding factor is that after having been buttered up she has to walk to his room. Also, on this particular occasion, she was not allowed to heal herself of her (relatively minor, but still painful) injuries before she went to the library. She did her research with shredded wing-edges and a black eye and an almost decorative crosshatch of bright red cuts down the backs of her legs. This is Thorn, so it wasn't thoughtlessness, but she hasn't speculated much on what it is instead, besides - Thorn.

She walks carefully -

There's a ripple in the air. She walks right into it.

And then she is elsewhere. She can no longer make meaningful progress towards her appointment, so she stops walking. Her eyes flick left, right -

Well. It would be hard for this to be worse.