What happens in Canto VII of Dante's Inferno?

Canto VII
Having just left Caccio and the others guilty of the sin of gluttony, Virgil and Dante descend into the fifth circle in Canto VII. This is the prison of those who in life had been greedy, wasteful, or engaged in meaningless work. Guarding the condemned is Plutus, the Greek god of wealth.
As the travelers come nearer to Plutus’s charges, he cries out,

“Pape Satan, Pape Satan, Aleppe!” *

(*Note: there is no agreement among scholars on the direct meaning of this exclamation. While all agree it is some sort of invocation of Lucifer, there is no direct translation for the word “aleppe. “)
Dante is frightened, but Virgil tells his charge to ignore the bellowing of the false god and demands that Plutus be quiet and let them pass:

"Let not thy fear
Harm thee; for any power that he may have
Shall not prevent thy going down this crag."
Then he turned round unto that bloated lip,
And said: "Be silent, thou accursed wolf;
Consume within thyself with thine own rage.”

The monster heeds Virgil’s words and falls back. collapsing helplessly just as sails do without benefit of wind.
Pausing as they enter the fourth circle, Dante observes sinners whose behavior remind him those unlucky travelers caught up by Charybdis. Charybdis is the sea monster of mythology whose thrashing tosses boats to and fro so relentlessly that vessels never make an inch of progress.
The sinners trapped here push heavy weight back and forth without ceasing; they too, never make gain any ground at all. The Avaricious (the greedy) push the weight forward while, simultaneously, the Prodigal (the wasteful) push it back. They continually admonish each other, shouting

"Why keepest?" and, "Why squanderest thou?"

As Dante observes the pointless battle, he notices that many of the participants have shaved heads, a sign of the priesthood. He asks his guide if indeed those souls had been clergy in life; Virgil confirms his suspicions. Dante tries to see if he can recognize any of those former men of the cloth among those furiously pushing but Virgil explains that they are so filthy that their identities cannot be discerned.
Leaving behind these sinners to their eternal task, the travelers come to the River Styx.