"La Jangada: Huit cent lieues sur l'Amazone" by Jules Verne is an adventure and detective novel published in 1881. When Joam Garral's daughter prepares to marry in Belém, Brazil, the family embarks on an eight-hundred-league journey down the Amazon River aboard a massive raft. But the seemingly prosperous father harbors a mysterious melancholy, and a cryptographic message sets in motion unexpected twists. The voyage combines biological and geographical discoveries of the Amazon with suspenseful intrigue about Garral's troubled past and secret correspondence with a Brazilian magistrate.