Keys of Hades

The Keys of Hades are magic "keys" owned by the god Hades. They have the power to "seal" or "free" people in the Underworld, which means someone can bring someone back from or send someone to the Underworld or Tartarus using the keys.

Percy Jackson and the Olympians

The Demigod Files

Percy Jackson and the Sword of Hades

One of the keys was placed inside the Sword of Hades. It is said that one touch of the sword can send or release a soul to and from the Underworld. The sword was stolen and Persephone feared that anyone who possessed it could release anyone from the Underworld. After Percy Jackson retrieved it through the events of Percy Jackson and the Sword of Hades, it is revealed that Hades had no part or knowledge in its creation. Knowing it would upset the balance of power between the Big Three, he was angry with Persephone for having it forged and swore an oath never to use it against the Olympians. Despite his anger about it's creation, it is assumed that he had used this same sword, the key included, in the Battle of Manhattan.

Items
Personal Weapons:	Riptide \| Annabeth's Knife \| Backbiter \| Master Bolt \| Poseidon's Trident \| Nico's Sword \| Thalia's Spear \| Aegis \| Ares' Sword \| Ares' Shield \| Caduceus \| Apollo's Golden Bow \| Silver Bow \| Artemis' Knives \| Hades' Sword \| Hades' Staff \| Kronos' Scythe \| Ivlivs \| Katoptris \| Hazel's Spatha \| Frank's Spear \| Reyna's Spear \| Juno's Gladius \| Annabeth's Sword \| Sumarbrander \| Gungnir \| Gjallar \| Mjolnir \| Gríðarvölr \| Khopesh \| Mallory's Serrated Knives \| Meg's Twin Imperial Gold siccae blades \| Thyrsus \| Hecate's Torches \| Minotaur's Axe \| Leroy's Sword \| Tyson's Javelin \| Alex's Garrote Wire \| Piper's Sword
Magical Items:	Annabeth's Yankees Cap \| Helm of Darkness \| Pandora's Pithos \| Winged Shoes \| Golden Fleece \| Flying Chariot \| Golden Apple \| Apples of Immortality \| Greek Fire \| Hermes' Multivitamins \| Nectar and Ambrosia \| Stygian Ice Whistle \| Keys of Hades \| Leo's Magical Toolbelt \| Serapis' Staff \| Magic 8 Ball \| Arrow of Dodona \| Pig Ball \| Mechanical Spider \| Angel Statues \| Athena Parthenos \| Chiron's Wheelchair \| Diocletian's Scepter \| Flaming Dodgeball \| Gleipnir \| Poseidon's Pearls \| Queen Hippolyta's Belt \| Mistletoe Arrow \| Frank's Stick \| Expand-o-Duck \| Caligula's Caligae \| Ran's Net \| Rune Stones \| Nábrók \| Pomegranate
Spoils of War:	Minotaur's Horn \| Medusa's Head \| Kampê's Scimitars \| Nemean Lion's Pelt \| Gorgon Blood \| Cornucopia \| Lydian Drakon Hide \| Phineas' Robe and Slippers \| Triptolemus's Almanac \| Odysseus' Astrolabe
Items:	Camp Necklace \| Chameleon Armor \| Daedalus' Laptop \| Golden drachma \| Denarius \| Red Gold \| Mark of Athena \| Thalia's Shield \| Video Shield \| Wristwatch Shield \| Golden Mango \| Sibylline Books \| Letter of Recommendation
Ships	Amos' Boat \| Argo II \| CSS Birmingham \| Egyptian Queen \| Julia Drusilla Yachts \| Pax \| Queen Anne's Revenge \| Reed Boat \| Naglfar \| Gorgyra's Canoe
Blessed Metals:	Adamantine \| Celestial Bronze \| Imperial Gold \| Stygian Iron \| Bone Steel