Canto XXXIII/1 The recapitulations that accumulate as this first part of Dante's trilogy draws to an end were often provoked by panic measures. Mistakes occurring at the very outset of the original book had to be pressed into service since the papermaking had been done and no more could be obtained. Thus I found myself with a whole set of spare versions of the image of the Dark Wood that opens the work; it seemed appropriate to try and use them at the end. Hell is frequently imaged as a prison throughout the poem; it is the prison within the prison of man's own error. This picture acts as a kind of condemned cell before the final release into the void of Evil Absolute which follows. Here, imprisoned, man looks out onto the claustrophobic imprisonment of his own mental state. This gaol is now imprisoned within the Book for a double eternity of the infamy that the inhabitants of Lower Hell so fear. As Ugolino betrayed his city by ceding fortresses to the enemy he is mewed up with his offspring in a fort whose key is thrown away. The words 'Breve Pertugio' refer to the aperture through which Ugolino perceives the passing of time. The bars that now pierce the book are themselves pierced to indicate that there is some small outlet still; i. e. for his grief via our pity. However, outside, he would only repeat his error, and the Dark Wood waits again for unpurged souls -- Source of annotation: Marvin or Ruth Sackner.