Virgil reminds him that in Hell what God wills is done.
This sentence refers to Inferno, written by Dance Alighieri. Virgil acts as Dante's guide into Hell, telling him what each of the characters did in order to get to Hell. Charon is the ferryman who took them across the river Acheron, although reluctantly.
The author will write where they feel comfortable, the author looks at all aspects of life for inspiration and therefore takes notes or writes when he/she feels the need.