Title: The Unknown War

Rating: K

Summary: Severus Snape, murderer of Dumbledore, has to leave England and fight in a war that he didn't know was happening. When he arrives he has to make one final decision and live up to his father's legacy while another door, one to happiness, is opened. Percy Jackson/Harry Potter crossover

Disclaimer: I don't own any part of this story and I'm not making any money off of it.

No one knew that an unknown war was going on at the same time that the Wizarding World was fighting another war, a war with itself. Albus Dumbledore, Headmaster of Hogwarts School of Witchcraft and Wizardry had been killed by the Defense Against the Dark Arts teacher and now Hogwarts and the Ministry of Magic was in the hands of Voldemort. Severus had been named Headmaster and he was ready to take his post when someone that Severus hadn't seen in years arrived on winged horseback.

"Severus Snape, son of Poseidon, your father needs you," Hermes told him.

"Why me?" Severus asked him.

"Cronus has fully escaped from the Underworld and his heading for Mt. Olympus with the rest of the Titans," Hermes answered.

Severus blood ran ice cold and without thinking about his job, or his vow, he got on the back of the winged horse and they both flew away.

Severus didn't ask any questions as they flew across the ocean. He had heard about Cronus from his history books and it had shocked him that he was the son of Poseidon. His mortal parents were long gone at this point but he had found out, during Harry's fourth year, that Lily Evens had been the daughter of Athena. It had upset him that her son didn't have any of his grandmother's talent and wisdom.

When they finally arrived the Titans were at the gates to Olympus and Hermes threw an old friend at him. He pulled the pen apart and it changed into Torment, the sword that Chiron had given him when he had first been recognized as Poseidon's son.

"Thanks," Severus said but Hermes went with him.

It was a horrible battle, with demigods falling to Cronus scythe. Severus shot him with freezing water and he howled in pain. He turned on Severus but Athena shot him with her spear, causing golden blood to come out. And then he noticed Hermione Granger fighting along aside a girl that he had never seen before.

"Kill my children," he howled and several female titans came at his father and stepmother.

"No," Severus whispered and ran after them.

One of the female titans shot something at them but it entered both Hermione and Severus bodies. Both of them had gone between the thing and their targets.

"NO!" Poseidon screamed, "NOT MY SON!"

"MY DAUGHTER!" screamed Athena

Severus felt his soul leaving his body, and saw Hermione's soul as well, and saw his Uncle shooting lightening at Cronus but then something strange happened. He and Hermione didn't start on their journey to the Underworld, but stayed there. Cronus, in the body of a demigod, raised his scythe but then it came down on him and he screamed as he turned to dust. Everyone cheered but Poseidon and Athena were holding their children's bodies.

"They saved your life, Hara," Zeus told her. "The least we can do is honor them with immortality."

Hara nodded and Severus felt his soul returning to his body. He turned and saw Hermione returning to her body as well, their red blood turning golden.

It took several days for Severus and Hermione to recover from death. Hermes delivered a message from the Underworld from Dumbledore, telling him that he had to get the staff's support if he was going to defeat Tom Riddle.

"Your Uncle wants to you stay in bed at least one more day," Hermes advised.

"Thanks, I will," Severus said and fell asleep.

The next day Severus and Hermione got on the horse and flew back to Hogwarts. When they arrived he sensed that something just wasn't right. He was also joined by Athena and Hermes.

"What's going on here?" Hermione asked, her golden eyes looking over the darken castle.

"I don't know but I intend to find out," Severus said and the four of them headed towards the castle.

They entered the entrance hall and suddenly Hermione was grabbed. Severus turned around to see Avery standing there, looking pleased with himself.

"Got a Mudblood here," he said.

"Let her go, Avery," Severus said, "That's my wife you're grabbing."

Avery and Hermione stared at him but since Hermione was the immortal daughter of Athena she quickly got over his words.

"What should we do to him?" Athena asked.

"Kill him, I don't care," Severus said.

"Traitor," Avery hissed but Athena took care of him and Hermione was saved.

"I hope you were only joking about me being your wife," Hermione asked.

"Well I was sort of hoping that you would be, since we're both immortal and fought the Titans," Severus said.

Hermione stared at him, "But I'm-."

"Can we make wedding arrangements later," Hermes said, "We need to find out what's going on."

Suddenly Remus and Tonks appeared and focused their spells on Severus. The spells hit him but had no affect on him because he was immortal. Athena raised her hand but Severus stopped her.

"They think I'm a murderer and I'm betting that the Order is trying to take control of the castle once more."

"Remus, Tonks, what are you-."

"Get away from him," Remus said, "He'll kill you like he killed Dumbledore."

Hermione shook her head and stood by her mother, her Uncle, and Severus.

"Get away from him or the next spell might hurt you," Remus said.

"NO!" Hermione screamed, "I'm not going to stand by and let you harm him."

"She's being controlled," yelled Ron Weasley.

"I think not," Athena snarled and Severus knew that she was itching to turn them into spiders or something.

"Hermione, get away from him," Harry demanded just as Bellatrix appeared.

"I don't think so," Severus said and he shot a torrent of freezing water at her, causing her to freeze on contact. "Filthy mortal in more ways then one."

"Your father would be proud of what you just did," Hermes said.

"True and I've always wanted to get her back," Severus told him.

"Get away from Snape," Ron said.

"Just stun them all," said Kingsley, "We'll sort through it when Snape's in Azkaban."

They raised their wands and then someone yelled "STOP!"

"That sounds just like Dumbledore," Hermione said to Severus and sure enough Dumbledore appeared, Hades behind him.

"Albus," Professor McGonagall whispered and then fainted.

"Your father thought that you might have some problems," Hermes said.

"Remind me to thank my father for his timing," Severus said.

"Lower your wands, right now," Dumbledore ordered, "Right now, Mr. Potter and Mr. Weasley."

Hermione saw Harry and Ron lowering their wands.

"I can't believe that I had to come up from the Underworld just to prevent you from blowing up the entire castle," Dumbledore snapped, "These two need rest and not spells shot at them."

"Sir, Snape-."

"That's Headmaster Snape," Dumbledore corrected.

"Yeah, him," Harry said, "He killed you."

"No, I asked him to do it," Dumbledore said, "I don't have much time as I'm not supposed to be out of the Underworld but Severus and Hermione helped their parents fight the Titans and died. Hara granted them immortality and I told Severus that he needed to return. And I was angered that they returned to this."

"But, he-."

"Harry, if your going to defeat Tom Riddle you need to put aside your hate for Severus," Dumbledore said, his form starting to fade. "If you don't then our world is lost."

And he was gone.

"They don't last long," Hermes said.

"So let me get this straight you're both stinking immortal," Kingsley said, not acting like himself.

"Yes," Severus said, "Now how many Death Eaters is there left?"

"None," Tonks said.

"Good, now let's strengthen the wards," Severus told them and they raced to get started.

As for Hermione Harry and Ron left Hogwarts to go and look for the different soul containers. Hermione knew that Ron hated the idea that Hermione would be staying behind but she was needed at Hogwarts. Severus appointed Remus Lupin as the Defense Against the Dark Arts teacher and Tonks as the new replacement Muggle Studies Professor.

"Let's just hope that she doesn't knock things over," Severus told Hermione.

Hermione smiled warmly at him, "I'm sure that she'll do a fine job."

"Ron's going to have problems," Remus told his wife.

"What do you mean?" Tonks asked.

"Well Hermione is hanging out with Severus," Remus told her.

"So what," Tonks said, "It's not like their on the same level that we're on. They fought against these giant people."

"The Titans," Remus said.

"That would be correct," said the voice of Athena.

They both turned to see the Goddess of Wisdom walking towards them.

"Their in-love with each other," Athena told them, "It happens a lot with demigods."

"Ron's not going to like it," Remus said.

Athena looked at him, "My daughter is a Goddess now and she doesn't need to hang around mortals that don't understand the fact that she will never grow old and never die. Mr. Weasley will make her life hard. Goddess that fall for Gods always follow their hearts."

"So Ron has no luck," Remus said.

"I'm afraid not," Athena said.

Hermione was so excited to finally marry Severus a few months later. She was already expecting their first child, a little boy, and she knew that this would be the start of a wonderful family. Ron had written to her, telling her that he was coming to take her away from the horrible Snape, but she knew that by time he came she would already be married.

"Do you, Hermione Granger, take Severus Snape to be your husband?" a Ministry official asked.

"I do," Hermione answered.

"Do you, Severus Snape, take Hermione Granger to be your wife?" the official asked.

"I do," Severus answered at once.

"You may kiss the bride," he told them and that's what her new husband did.

During the feast Harry and Ron appeared and Ron screamed when he saw Hermione taking a piece of cake that her husband offered.

"How could-."

The sound of birds drowned Ron out and both of them knew that more monsters were appearing.

"Talk to you later, Ron," Hermione said, as she brought out her shield and sword.

As they left they didn't hear Ron asking, "What does old Snape have that I don't?"

"I don't think that you really want the answer to that," Remus said.

Seven Years later….

A small boy walked past the tree that marked the boundaries for Camp Half-blood and Chiron was there to greet him.

"Welcome to Camp Half-blood, William Snape, son of Goddess Hermione and God Severus, Minor God of Truth."

"Thanks," William said and deep down he knew that he would have the time of his life.

Four Years Later…

William entered the Great Hall along with the rest of the new students. He was looking forward to begin his mortal training despite being immortal. His sister was due to start Hogwarts next year and he knew that she would be a fierce fighter, like he was.

"Lupin, Agatha," was called.

A girl came before the hat and it was placed on her head. "GRYFFINDOR!" the hat yelled and the Gryffindor table cheered as she joined their ranks.

The sorting continued and finally it was his turn. He walked over and the hat was placed on his head.

"Well I never thought I would see a Snape under my hat again," the hat told him. "Your parents would be so proud that you're here."

"Thanks," William said.

"Well I know where to put you…GRYFFINDOR!"

The Gryffindor table cheered as he took the hat off and he went over to their table. William knew that his parents would be proud.


A/N: It took me a couple of days to write this because I wanted to make it the best that I could make it. I'm going to do one where William and his sister go on a quest but not a quest that Percy would go on, one that's very important and one that connects the future of their parents.