The Freshwater people is being chased by the saltwater people, since the saltwater people wanted to take away the freshwater people's women.
They are approaching the most sacred part of the river, where they have to be completely silent to respect the land. They have been taught by their elders to be completely silent when passing through this section.
The Freshwater people stopped rowing, and became completely silent, even though they are in a pursuit with the Saltwater people.
The Saltwater people did the opposite, making tons and tons of noises and splashing through the sacred land.
The Saltwater people's boat suddenly hit a sand bar, but as they slowly realise, they noticed that it isn't a sand bar, but it was a giant serpent.
The snake then sunk the boats they are in, throwing all of them into the water. They tried escaping, but the serpent has created a whirlpool, sucking and drowning them.
This story is the reason why you, the reader, should be respectful of the land around you, which used to be own by the Indigenous community, to be silent to respect them.