Following the encounter with Lucifer, Dante and Virgil find themselves in a dark place recognizable by the sound of a stream, the Lethe, the river of forgetfulness. Without resting, the travelers follow the river to return to the world of light.
Canto XXXIV, 127-132
A place there is below, from Beelzebub
As far receding as the tomb extends,
Which not by sight is known, but by the sound
Of a small rivulet, that there descendeth
Through chasm within the stone, which it has gnawed
With course that winds about and slightly falls.
Canto XXXIV, 133-139
The Guide and I into that hidden road
Now entered, to return to the bright world;
And without care of having any rest
We mounted up, he first and I the second,
Till I beheld through a round aperture
Some of the beauteous things that Heaven doth bear;
Thence we came forth to rebehold the stars.