Odyssey
On his journey home, Odysseus lands on the island of the Cyclops Polyphemus.  They go inside his cave at the sight of sheep, cheese and milk.  Polyphemus catches them and eats some of Odysseus' men.  Odysseus tricks and blinds him and they escape.  The Cyclops prays to his father Poseidon that Odysseus would not get home to Ithaca and if he was fated to make it home, Odysseus would lose all of his men, his ship and find trouble at home.  This prayer becomes the plot line of the Odyssey.