Homunculus

In my mynd there is a train
That all the rails and rivets bend
With driver stood axtride the deck
No fear, she, of blame nor wreck
But boils the furnace of the race
With ‘Wretch!’ and ‘Wry!’ etched on her face
With wretch and wry creased deep upon
The passengers cling on and on.
And in her Bbbbbrain, another train
With wheels that churn and spin
[Into [the [sand [embedding [deeper]]]]
Elbow-pistons rusting in
Its driver paralysed with shame
And carriages bewildering...
While under heaven's shining s?n
The passengers cling on and *n.