| Across |
| 3. | Percy is able to control this element |
| 5. | Another name for children of the gods |
| 8. | Medusa's hair is made of these |
| 11. | The ferryman to the Underworld must be paid in these coins |
| 12. | Grover earns these and becomes a "real" protector |
| 14. | Luke gives Percy a shield and this "gift" from his father |
| 15. | Percy's mortal mother |
| 17. | Goddess of Love |
| 19. | Hade's wife; saves Percy and the others from Hades |
| 21. | Percy's friend and protector |
| 22. | Betrays Percy and the others by stealing the thunderbolt |
| 23. | Lord of the Underworld |
| 26. | Name of the camp for children of the gods |
| 27. | Poseidon's three-pronged spear |
| 28. | This monster has many heads |