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