"Well, that's promising. Now I want to see if I can make it completely uniform in there," she says, getting up to collect the rocks. Then she puts them away, replaces them with twice as many clear glass pebbles, and sits back down in her chair outside the circle.

Rook! Don't you just dream of perfect calm and quiet? Yes you do. Well, Castle is here to help. Be serene. Be sturdy. Be clear.

There isn't even an image this time, just a sense of stillness in the air. Castle thanks the rook.

The harmonics outside the circle are mostly unaffected - the patterns have smoothed out a tiny bit, maybe - but the harmonics inside the circle are now perfectly flat.