How do you get the trident from Poseidon on mythology island?

After Zeus claims the five sacred items, Hercules agrees to help you. Take him to the underwater maze and he will kick away the large rock so that you can reach Poseidon.

You will need the TouchScreen Mirror from Aphrodite, because Hercules doesn't like to walk. On the beach in Poseidon's realm, the answers to her quiz are Ares, Hermes, Aphrodite, Artemis, and Hestia.