What do we know about the nature of visions that occur at the time of death? And how do they relate to what we see every night in a dream? To open the veil of mystery and unravel their meaning, this is what the wanderer will have to do during the journey "in the darkness of the valley".

The divine comedy begins with the words:

Earthly life having passed up to half,
I found myself in a gloomy forest,
Having lost the right path in the darkness of the valley.

…

I do not remember myself how I entered there,
So the dream entangled me with a lie,
When I lost the right track.

So what are the visions that arise in consciousness at the time of death? Whose are they and why are they so sad?