It seemed that out of the battle I escaped
Down some profound dull tunnel, long since scooped
Through granites which Titanic wars had groined.
Yet also there encumbered sleepers groaned,
Too fast in thought or death to be bestirred.
Then, as I probed them, one sprang up, and stared
With piteous recognition in fixed eyes,
Lifting distressful hands as if to bless.
And by his smile, I knew that sullen hall;
The idea of the poet ‘probing’ the dead prisoners and one springing up has a nightmarish,  gothic  quality.