It cannot be seen
Because
Nothing's there.
It cannot be felt
Because
Nothing's there.
It can be heard though...
It sounds like the mouth of a cave
Or miles of catacombs.
There's nothing to touch.
Nothing to smell...
But it can be felt.
Inside.
It creeps up on you
With the sound
And pulls the ground out
From under your feet.
Where it comes from
I haven't a clue...
Do you?