A poem on the underground wall

The last train is nearly due The underground is closing soon And in the dark deserted station Restless in anticipation A man waits in the shadows His restless eyes leap and scratch At all that they can touch or catch And hidden deep within his pocket Safe within his silent socket He holds a colored crayon Now from the tunnel’s stony womb The carriage rides to meet the groom And opens wide and welcome doors But he hesitates, then withdraws Deeper in the shadows And the train is gone suddenly On wheels clicking silently Like a gently tapping litany And he holds his crayon rosary Tighter in his hand Now from his pocket quick he flashes The crayon on the wall he slashes Deep upon the advertising A single-worded poem comprised Of four letters And his heart is laughing, screaming, pounding The poem across the tracks rebounding Shadowed by the exit light His legs take their ascending flight To seek the breast of darkness and be suckled by the night