What is Empty Graves?

The empty graves are a warning and an omen. The Night Digger digs six graves near the tree for Molly, Kip, and the Windsor family, expecting them all to succumb to greed and the tree. The graves are a reminder that they can still fight greed and turn their lives around. When Molly shows Bertrand the graves, Bertrand stares his own future in the face unless he changes. He therefore has a moral awakening that compels him to flee the island with his family to save them.