Golden Egg's Riddle

'Come seek us where our voices sound,
We cannot sing above the ground,

And while you're searching, ponder this:
We've taken what you'll sorely miss,

An hour long you'll have to look,
And to recover what we took,

But past an hour - the prospect's black
Too late, it's gone, it won't come back.'

THE EGG AND THE EYE - Pg 390