And that the bats have been waiting so very long for him to arrive.
Spenlow feels that he had known this all along but only now did he realise it.
He finds it impossible not to try and touch the key. As he reaches out, the key floats up to meet his hand. It starts to glow.
It is humming softly.
There is a rippling in the water and three glovefish break the surface and begin to circle the boat. The largest fish is now also glowing. One of the pale cave crickets that was chirruping the melody has hopped onto the horn. Stiggins the dog watches as the very ends of the insect's antennae start to glow faintly.
The soft, soothing light pulses slowly, hypnotically, in the darkness.