Mrs. O'Leary, a hellhound, shadow-traveling.
| “ | All shadows are part of the same substance. There is only one darkness, and creatures of the Underworld can use it as a road, or a door. | ” |
–Nico di Angelo explains shadow travel to Percy Jackson in The Last Olympian. | ||
Shadow Travel is a form of transportation that allows creatures of the Underworld and demigod children of Underworld deities to travel to any desired place on Earth or in the Underworld, although it makes the user extremely fatigued.
Shadow Traveling[]
Hellhounds and children of Hades use this traveling method by slipping into the shadows and coming out somewhere else of their desire. Children of Pluto can also shadow travel, as shown by Hazel Levesque in The House of Hades.
Exactly what happens in the shadows is not known. It is to be assumed that it does not simply take them there, but acts as a tunnel, as when Mrs. O'Leary shadow traveled she was still running after they got into the shadows when Percy Jackson and Nico di Angelo were traveling to Westport, Connecticut to find May Castellan. Percy describes how it feels to shadow travel as "going so fast that it feels like your face is peeling off."
Shadow traveling exhausts the user greatly; for example, Nico said that he passed out for a week in China when he first tried it, and Mrs. O'Leary herself was tired after doing it. The more you do it, the more you lose contact with the physical world.
Deities such as Hecate, Persephone, or Hermes can enter or leave the Underworld at will. Hence, their demigod children can probably shadow travel as well, if properly trained.
Percy Jackson and the Olympians[]
Nico di Angelo, a son of Hades who is able to shadow travel.
The Demigod Files[]
The Sword of Hades[]
Persephone sent a shadow to Nico's location and apparently, forcefully shadow traveled him to New York to join Percy and Thalia Grace. This was not mentioned as being shadow travel though.
The Last Olympian[]
Shadow traveling was first shown by Mrs O'Leary, who took Nico and Percy to May Castellan, Luke's mom, at Nico's request to figure out Luke's trail and memories (and to better help Percy fight Luke since it was realized that Luke had taken a bath in the River Styx). Later, the hellhounds from Kronos' army shadow traveled inside the defenders' borders to attack during the Battle of Manhattan. Nico is also able to shadow travel, but it requires a lot of effort and it leaves him exhausted.
The Heroes of Olympus []
The House of Hades[]
After an attack from the mountain gods, Nico mentions that he could shadow travel past the mountains if he were on his own and his strength was up.
When they reach the House of Hades, they are separated. Frank calls in a favor from the dead to transport the Seven to where Hazel is battling Clytius. It is unknown what type of travel this is, shadow or other. After the battle with Clytius, the ceiling starts to break and crumble. Hazel asks Nico whether he could shadow-transport them, but Nico says he can hardly transport himself. Then, Hazel offers to help and they both successfully transport the entire team to a hillside overlooking the River Acheron. Nico then offers Reyna his help to transport the Athena Parthenos to Camp Half-Blood via shadow travel.
The Blood of Olympus[]
Nico shadow travels himself, Reyna, Coach Hedge, and the Athena Parthenos to Camp Half-Blood to prevent a civil war. Along the way they have an incident in Albania, fight earthen shells in Pompeii, fight lycanthropes in Portugal, go on a cruise ship, fight Orion in Puerto Rico, and fight zombies in South Carolina. The effort involved nearly kills Nico before Gleeson Hedge summons Pegasus and several other pegasi, including Blackjack and Guido, to help finish the journey by air.
After finally arriving at Camp Half-Blood, Nico considers using shadow traveling to try and assassinate Octavian despite his weakened state, but he's stopped by Will Solace who can tell just how close the son of Hades is to melting into the shadows for good.
The Senior Year Adventures[]
Wrath of the Triple Goddess[]
Percy summons Mrs. O'Leary who shadow travels from presumably Camp Jupiter to join him. Shadow traveling across the country exhausts the hellhound who disappears into the shadows to rest after helping Percy to find Nope the hellhound puppy.
Hecuba proves to be capable of shadow traveling as well, dragging Percy with her after the demigod tries to put a leash on her. The rough ride compared to traveling with Nico or Mrs. O'Leary makes Percy think that his friends may have been shielding him from the worst of shadow traveling's side effects, something that Hecuba doesn't care enough to do. Hecuba eventually stops at the ruins of Troy before taking them both back to Manhattan after Percy convinces her to go home. Like with Mrs. O'Leary, shadow traveling so much and so far exhausts the hellhound.
The Trials of Apollo[]
The Hidden Oracle[]
During Nero's Skirmish at Camp Half-Blood, Nico and Will Solace shadow travel to hijack a flying Chariot from Sherman Yang for Apollo to attack the Colossus Neronis. After this Nico passes out.
The Tower of Nero[]
In order to escape the tauri sylvestres, Nico shadow travels first Rachel and Will, then comes back for Meg McCaffrey and Apollo. He takes a nap to recover, sleeping on a travel pillow Will carried and then eats a KitKat when he wakes.
The Nico di Angelo Adventures[]
The Court of the Dead[]
Nico shadow travels himself, Will Solace and the Coco Puffs from Camp Half-Blood to Camp Jupiter, although it leaves him tired.
Hazel later uses shadow travel to bring Nico to the Caldecott Tunnel. This is the first time that Nico ever shadow travels as someone else's passenger which proves to be a violent sensation for him. Nico then uses shadow travel to get himself and Orcus to safety, prompting a slew of questions from Deion about the ability.
After being captured by Printhous, Hazel tries to shadow travel out, but it doesn't work.
Later, Nico is easily able to shadow travel himself, Will and the Coco Puffs from Camp Jupiter to Camp Half-Blood.
Side Effects[]
In The Blood of Olympus, one side effect was shown besides exhaustion and fatigue: overexertion of shadow travel can cause the user's molecular structure to begin to fall apart, gradually turning them into shadows and losing themselves. Due to Nico pushing himself to bring the Athena Parthenos to Camp Half-Blood, he began to lose himself, even entering a "shadow coma".
In Wrath of the Triple Goddess, while getting dragged through shadow traveling by Hecuba, Percy Jackson finds it to be far more uncomfortable than shadow traveling with either Nico or Mrs. O'Leary. As a result, Percy suspects that Nico and his hellhound have been protecting him from the worst of shadow traveling's side effects.
In The Court of the Dead, while shadow traveling as Hazel Levesque's passenger, Nico experiences a violent sensation, feeling like a piece of origami being twisted and folded over and over.
Users[]
Gods[]
- Hades/Pluto
- Persephone
- Nyx
- Erebos
- Hecate
- Thanatos (possibly)
- Melinoe (possibly)
- Hermes (possibly)
- Nemesis
Demigods[]
- Nico di Angelo
- Hazel Levesque
- Other unknown children of Hades/Pluto
- Demigod/legacy children of Underworld deities
Mrs. O'Leary, a user of shadow travel.
Hellhounds[]
- Cerberus
- Mrs. O'Leary
- Hecuba
- Other unknown hellhounds and monsters
Trivia[]
- In other literature, shadow travel is sometimes referred to as Umbraportation.
- Shadow travel is an ability that seems to be shared by most, if not all, Underworld monsters and deities, meaning gods like Thanatos and Melinoe may also have this ability, but haven't used it in the series.
- According to Hylla Ramírez-Arellano, Shadow Travel is magic.
- In The Tower of Nero, Will states that the best treatment for the negative effects of shadow travel is kit-kats and sleep.