Answer:
Odysseus tells the Cyclops his real name.
Explanation:
After making the fool of Cyclops and blinding it, Odysseus finally manages to escape. Nobody gives a helping hand to the cyclops when he is injured because of Odysseus who tells the cyclops that his name is "Nobody" and the cyclops yell that "Nobody is trying to hurt him".
When Odysseus escapes, he commits a mistake and tells the cyclops his name which causes the cyclops to ask Poseidon to do something to Odysseus and Poseidon responds by attacking the ship.
