"The cyclops Polyphemus traps Odysseus and his men in a cave, behind an enormous rock. Only the cyclops is strong enough to move the rock, so Odysseus can’t escape. Instead, Odysseus hatches a plan. [...] Odysseus’s escape from Polyphemus demonstrates his main character trait: a gift for tactics and trickery. It’s significant that Odysseus’s stratagem requires him to conceal his reputation and identify himself as “Nobody.”"
Reference: SparkNotes LLC (2019). SparkNotes: The Odyssey Key Questions: Five Key Questions. [online] SparkNotes.
This question has no answer because it does not give any information on the letter, Juans situation, or anything other than the fact that he is sending a letter