Neither shape nor shadow

Neither shape nor shadow
In the space of one night's darkness
They have gathered, somehow drawn
To where sand and water meet
To the place where nature mourns
An army of one thousand souls
Moved not by force of law
But by an end of which they dreamt
Returns to wade once more

In the shallows, but a prelude
To the greatest icy depths
Where neither shape nor shadow
Can persist in one who's stepped
Their unseeing eyes surveying
Darkened scenes within their minds
Now blissful, soon will falter
Laying bare what now it hides
Once submerged they may awaken
Briefly grasping moonlit skies
But a crescent moon accompaniment
Merely ushers in the tide
Beneath horizons megalithic
Rays of light's first wonder
Shall reveal an ashen shoreline strewn
With the prints of those pulled under