What does Silas see and hear when he and Marshal Farmer enter the bog?

Silas and Marshal Farmer enter the bog, and Silas begins to hear voices. They sound like hundreds of people conversing all at the same time. Then Silas starts seeing forms out of the corner of his eye. When the shapes sharpen, he realizes they are dead people--young, old, and children. The ghosts are covered in the wounds that killed them.