It was like hearing a song over a great distance at first, carried on the wind, or deep beneath the surface of the water.  The melody-- though it wasn't precisely a melody, in the strictest sense, more like a swirl of resonance that coalesced into a rippling chorus-- slowly filled her mind with hues of brilliant, kaleidoscopic blue, and as they drew close to the crystalline pool, the song grew louder, more intense.  It was as if her senses had begun to open up like a flower to the sun, stretching towards the echoes that brushed agains them.  The song swept over her entire being, and she could sense a curling refrain of curiosity weaving through it as it touched her mind.

Something in her shifted, gently and almost imperceptably, like slipping between the waking world and a dream, and she slowly sank to a crouch by the lapping edge of the pool, reaching one hand forward until the tips of her fingers dipped into the cool water.  "Can you hear the song?" she asked the Doctor softly.  "Sometimes I can hear bits and pieces of... of music, though it's not really a human idea of music.  I don't know how to explain it.  I hear it in the trees, the wind, the water, wherever I go... but here... here, it's so much... louder.  More alive.  Aware.  Can you feel it?"  She lifted her head and tilted it to look at him.