Samhain was a Gaelic festival marking the end of the harvest season and the beginning of winter or the "darker half" of the year. Traditionally, it was celebrated from October 31st to November 1st in Ancient Times, as the Celtic day began and ended at sunset. This is about halfway between the autumn equinox and the winter solstice.
In celebration, special bonfires were lit. These were deemed to have protective and cleansing powers and there were rituals involving them. Samhain was seen as a liminal time, when the boundary between this world and the Otherworld could more easily be crossed. This meant the 'Aos Sí' (the 'spirits' or 'fairies') could more easily come into our world.
Over time, Samhain and All Saints'/All Souls' merged to create the modern day Halloween.
A Samhain Story
Leo Valdez fought to keep his eyes open as the heat of the roaring flames and the murmuring of his companions threatened to lull him to sleep. A peaceful contentment settled deep in his chest. This was where he belonged and where he truly felt wanted. Nestled in a quaint little glade somewhere deep in the woods beneath the inky emptiness of a sky without a sun or moon while the world slumbered on around him.
"And oh, how our hero was mistakened! Just as she ran to the light, to freedom; sword raised and dagger ready; a skeletal hand came out of nowhere, snagged her hair and yanked her back!"
Leo felt a smile tug at his lips, despite the story's perturbation. He clutched a small piece of sea glass that somehow found its way into his pocket. He could not recall how or why it was there, but he had taken to caressing it for reassurance.
The eyes of his friends around the crackling flames were wide with eagerness and their bodies were taut with anticipation. Will Solace was griping Nico Di Angelo's hand so tightly that his knuckles turned white, while Di Angelo was simply staring off in another direction. The boy had seen too many horrors in Tartarus to be phased by fictional ones.
Hazel Levesque's foot nervously tapped out a beat as Percy's story took a dark turn and Frank Zhang put a comforting hand on her arm. Calypso, his lovely Calypso, wore a tight smile and wide eyes while Reyna Avila Ramirez Arellano simply scoffed, and Bianca Di Angelo told her to hush up, she was listening to the story. Annabeth Chase simply shook her head fondly as she watched her boyfriend chatter on. Piper McLean leaned closer to Jason Grace and hid her head in his chest.
"She was caught by the sandman. Down, down, down she tumbled, into the darkness. It swallowed her whole. Both were never seen again. BUT! On certain nights when there's just the right amount of shadows and silence, some people say you can still hear her screams from 6 feet under... just like tonight!"
Percy let out a blood curdling scream and threw pig fat in the fire, making the flames dance and leap and illuminated terrified expressions. His audience muffled startled shrieks and Leo clapped his trembling hands with enough force to send tingles shooting up his fingertips.
"Well done, well done!" Bianca said as she stood.
"That must've been your best," Hazel praised, face as white as a ghost.
"I doubt I'll sleep tonight," Frank remarked, trying to put on a brave front.
Jason laughed and said, "Spectacular dude, but was the scream really necessary? Piper here almost fainted out of fear." Which earned him a swat on the head.
"It was a perfect ending. It added to the effect! Though, my throat is a little dry," Percy laughed.
Calypso passed him a cup and he downed the contents in one gulp. The son of Poseidon immediately developed a healthier look.
"You really had everyone there," Leo said fondly.
Percy grinned into his drink, eyes crinkling as though he had a profound secret.
A soft chuckle echoed throughout the camp site, prickling the hairs on the back of Leo's neck and he turned to Nico Di Angelo. In all his brooding glory, the son of Hades untangled himself from their friends and stood. The boy lazily glanced around the clearing and Leo couldn't shake the unnerving chill that stole over him as he briefly met Nico's stare. It was like staring into a starless night. And the glint in those eyes unsettled him.
What had he seen?
"Nico? You alright?" Will was saying. Concern laced his voice. Leo felt the tension leave him as Nico took his seat. At least he wasn't the only person who found the boy's strange behavior odd.
"Your story is last," Hazel told her brother. "It's your turn to share." She tucked a brown lock behind her ear. A little wooden butterfly shined in the firelight. Leo had given her that pin for her birthday. He planned to tell her how he felt but when the time came he practically threw the box at her and ran the other way. But that was before Calypso.
"Then Will decides who wins."
"Which I say is utterly unfair because he's biased!" Reyna called. Bianca hushed her again.
Nico sighed dramatically and stalked to the center of the circle, as close to the fire as he dared. He spread his arms as if he was going to embraced them all, and began to speak.
"It was a dark and stormy night…"
"Oh my gods," said Bianca, grinning toothily. "Could this be any more of a cliché beginning?"
Nico sighed. "No, wait, me try this again. There... was once a small, quiet town at the edge of a city. Nobody payed much attention to the town, and in return it largely ignored the city. The town was peaceful and simple, and—"
"Wait, what category is this?"
Nico scowled. "What?" If looks could kill, Jason would be dead. He never appreciated interruptions.
"Every story has a category," Jason explained. "That's how the contest works, remember? Calypso's was a mystery, Frank's was supposedly based on real events—" (to this Frank snorted) "—and Percy's was a childhood fear. Which leaves you with..."
Di Angelo pressed his lips into a thin line. "Murder."
Uneasy looks were exchanged around the fire and a dangerous somberness befell the group. A change in the atmosphere shifted as if it was brought by the wind. Ravenous mist devoured the cheerfulness of the night and innocent shadows flourished and swelled ostensibly at the edges of the campsite without the group's laughter to keep them at bay.
Leo took in the mood shift with sharp, calculating eyes.
"I think it's unwise to bring up such a subject on a night like this," Calypso rasped, biting her lip so roughly he feared she might draw blood.
"What? On the night they were kil—"
"She means on Halloween," Piper correctly him gently.
"She liked to call it Samhain," Percy mumbled gruffly.
"Who?" said Leo, failing to follow this strange, broken conversation. They had lost so many in the war.
"You don't remember?" Annabeth said. She turned to Reyna for help, but for once the Praetor was silent.
Hazel wrung her hands, eyes shinning in the firelight. "We shouldn't talk about the dead. Not like this..."
"I didn't bring it up!"
The son of Poseidon closed his eyes as if he was in pain.
"What happened?" Leo asked. "Was it the war? A quest?"
Bianca shook her head as of saying not now.
"Perhaps we should turn in," Will said softly. Slim fingers wove their way through gold curls. He was greeted with a heavy silence that was interrupted by a crackling log. "S'late..."
"Wait," Nico whispered. "Let me finish." All eyes fell upon him, resuming a scene identical to the one at the beginning of the night. He closed his eyes as if he was praying, and they held their breaths as he held his.
"Nico..." started Will as seconds crept into minutes.
"There is a certain... magic… in speech. When crafted properly, words create stories, and everyone knows that stories hold an even greater power. Humans are enraptured by stories, as are animals and monsters and other beings. On an evening such as tonight with the veil to the Underworld so thin, our stories could very well possess the capability of catching the attention of folks we have not seen for a terribly long time. Who knows what such power can achieve?"
"What is he talking about?" Leo murmured.
"Honestly, Leo," Reyna sighed, facing him. Her black tresses danced in the wind. "With all the mentality ability of yours that was used to create Festus and the Argo 2, one might actually be deceived into thinking you had a brain."
"Hey!"
"But, in his defense, once might've thought you would be better at defending your gates from a single midget after years of battling monsters."
Reyna smiled at Annabeth with mirth in her eyes. "Touché."
"Wow. Thanks," Leo grumbled.
"He's lost it," Frank snorted. "Completely lost it."
"No, I haven't." Nico held them with a stare to rival the gods'. "Can you see it? Can you hear it? Listen!" And then he began to hum a hauntingly beautiful tune.
And slowly but surly, as the group strained their ears, they became acutely aware of the melody that echoed from the trees. It swallowed them up and enveloped them whole, and Leo found his face damp with tears. He didn't know how or why, and in that moment he didn't care.
Then, at the edges of the scene, stood a group of shadows. One turned to Leo. Still beautiful and exactly as he remembered her.
Mom?
Leo was torn between rushing into her arms and remaining frozen on the spot, afraid he would shift wrongly and she would vanish. So he watched with baited breath as she gracefully crept closer, a smile at her lips. He clung to her tightly as she brought him into her arms for the very first time in a many years.
"I've missed you so much. So much." Leo gently pulled away after a while, brushing away her tears with the back of his palm. "These are my friends," he said at last. "My family."
Annabeth dipped her head in respect and Reyna offered her a tight smile, and Bianca greeted her like an old friend. The others were too pale to respond.
"But wait," Hazel said, stiffening. "I sense something too. Something else. Something... more."
"Is it a friend or foe?" Annabeth demanded, reaching for her knife.
Leo gave himself whiplash as he turned to look at the shadows once more; they had duplicated in size and now bore faces he knew.
"Is this a sort of prank?" Calypso whispered, brow furrowed. Leo had wondered the same thing at first. "Something involving the Mist? This isn't funny, Hazel!"
"Is she all right?" Frank asked Will, as if he might know why his boyfriend and his boyfriend's sister were acting so strangely. Will simply shrugged as if to say it's a Hades thing.
"Can't you feel it?" The daughter of Pluto cocked her head, scanning the foliage above and the ferns below. "The presence... you'd think I'd know it anywhere... had I realized who it was…"
"—it's them," Nico finished for her. "It's always been them. Even I had underestimated the power of our tales, for I realize now that all who have left us have returned to listen to our words. Luke and Ethan and Michael Yew and Zoë, and all the heroes who fell before them."
"And those who fell after?" Percy croaked.
"They're here too," Nico reassured him. "They're all here. Every hero. Every halfblood. Every and any family of ours that left us — they're here." He turned his face to Bianca. "My sister…"
Bianca went to embrace him, but her fingers passed through his like smoke. Her lips trembled as she quietly retreated into herself.
Nico turned to Jason, tears in his eyes, and cleared his throat. "Reyna is here too."
"And Annabeth?" Percy said, eyes hauntingly sad.
"I'm here, Seaweed Brain, I'm here," the blonde whispered. "I'll always be with you."
Nico nodded, and the boy broke down in gut wrenching sobs.
"And one more. He sits near Calypso, and I suspect he's been at her side all evening."
The goddess turned, tears collecting in her beautiful eyes; and the first time that night, Calypso was looking at Leo.
The son of Hephaestus clutched the sea glass, a gift from her island she bestowed upon him on their anniversary so many years ago, and mourned that she couldn't truly see him.
"Their time is almost over," Nico and Hazel said together. And sure enough the shadows began to dispatch and the singing grew fainter in their ears.
A pit grew in Leo's stomach, for it felt as though they were saying good bye all over again, and after they had just reunited. One by one, the visitors began to take their leave. Bianca blew Nico a kiss before walking to the edge of the woods where she took Maria Di Angelo's hand and the two departed. Reyna gave Jason and Piper one last look, and a smile came to her face. She trailed away too, her sister by her side.
Leo simply stared at Calypso. He would stay there all night, were it not for not the voice in his head that warned him of the consequences of staying past sunrise. He silently told her all the things he wanted her to hear; how he loved her and missed her and how he so regretted leaving her despite not knowing how or why... and somehow he knew, deep down, that in a way, she would hear him after all.
Leo finally stood from his seat and paused and wondered aloud, "How did it end?"
"You don't want to know," Annabeth said softly. He had almost forgotten about her. She was so close to Percy she could almost touch him, but they both knew it was impossible to do so. She so wanted to comfort him.
"Was it worth it, then?"
"Look around you, Leo."
"They're in pain," he said, taking his friends' solemn expressions. "They're miserable. How is their suffering worth anything? How is that fair?"
Annabeth gazed at Percy, a clear longing reflected on her face. "I never said it was fair. Nothing in life is fair. Especially the one we led... but look to their weapons. Look to their swords and daggers and arrows and staffs."
The boy scanned the clearing. Not an ounce of celestial bronze could be seen. "They don't have any."
"Precisely." This was the first time Leo had seen the daughter of Athena smile in a very long time. "They have you to thank for that. Because of you, they have no use for their weapons any more. They don't need to live in fear or in hiding. They lead normal lives, now, among normal people. And it's all because of you."
This left him with a multitude of burning questions but the knowing glint in Annabeth Chase's gray eyes that made her look so much like her mother would be his only reply.
"The veil closes soon. We must leave when we can."
Leo glanced at his friends one last time. Tears twinkled in Percy's eyes as he called out to someone who couldn't reply. Piper and Jason watched the fire dance, their minds a thousand memories away. Frank sat with Hazel; whispering sweet things in her ear. Will rose from his seat and approached Nico cautiously as the boy spoke to things that couldn't be seen. And Calypso, his Calypso, simply stared at the spot where he once sat beside her in wonder.
"C'mon Repair Boy," Annabeth said. She seemed weary and tired. She gave Percy one last look before rising.
"I'll wait for you," Leo swore to the stars. He clutched the sea glass as tightly as he could.
The pair slowly wove their way through the trees. The fire dimmed behind them. If they turned back, they would hardly be able to see the group at all.
"We'll see them again," Nico was saying. His voice was faint. "At the next Samhain. All we need to do is speak our stories, and they will come. Always."
Shadows became mere shadows once more, the living and dead were divided again, and stories became just a jumble of powerless words as the two vanished into the night.