A/N - So Finnie, Queen of Crossovers, has returned to post yet another PJO-related crossover! *giggles* This story is in what I've dubbed the "IU" - a crossover AU that involves Percy Jackson, NCIS, Dalton and now Sherlock (Plus my novel!). It's my distraction project. My I'm-in-class-right-now-need-something-to-do-with-my-hands project. I have what adds up to a couple chapters written so far, so I'm gonna type it up and try to find good spots to break up the chapters [in the notebook it's written in it just has line breaks for jumps in time]. I know I've got a whole bunch of works-in-progress posted in part up here, and I'm sorry that I haven't updated them more/more regularly. *shrug* It's just how my brain works.

One: A Collision of Worlds

"Just a point of interest, whose idea was it for us to shadow-travel here?" Clarisse asked, catching Nico as he stumbled.

"That would be mine," the 15-year-old responded. He tried to regain his balance. The others – Terra, Percy and Annabeth – slid off of Mrs O'Leary's back. "I mean, Perc and I couldn't exactly fly here, could we? Plus crossing the Atlantic by air or sea takes too long."

"Wouldn't want to keep a crime scene waiting, would we?" Tera said. "You alright, di Angelo?"

"'course I am," Nico replied. Percy chuckled, putting his hand on Nico's still unsteady shoulder.

"We should check into the hotel, guys," Annabeth said reasonably. "It should be just around the corner here."

They followed Annabeth into the hotel, and for once they accomplished something uneventfully.

Within the hour, they were approaching a house that was clearly a crime scene. Terra adopted her 'yes, I am qualified to be here' attitude and pulled out her badge and ID.

"You're the Americans?" the irritable officer waiting for them said. "Sergeant Sally Donovan." She held her hand out to Terra.

The 18-year-old shook her hand. "I'm Agent Terra Forman. Gr- Lestrade is expecting us, as you know. Where is he?"

"Second floor, first door on the left."

They walked to where they'd been directed to, and as expected found Detective Inspector Lestrade waiting for them. What they weren't expecting where the man with curly dark hair and his shorter, light-haired friend looking closely at the body. Terra and Annabeth both embraced Lestrade.

"Hello, girls," he greeted them. He nodded politely to their teammates.

The curly haired man turned around. He stared at the group that had just entered the room. Ignoring this, Terra ordered, "Nico, body."

Her youngest team member nodded and joined the other man next to the body. "I'm Nico."

"Dr John Watson," responded the man.

"Beth, evidence," continued Terra. "Riss, photos. Perc –" She glanced around. None of his usual jobs were currently available. "…help Annabeth."

Her team did as they were told, leaving Terra in the doorway with Lestrade. The other man was still staring at her, which she found mildly disconcerting.

"Greg, who is this man?"

"Sorry 'bout him, Terra. He's not exactly great with people."

"That still begs the question – who is he?"

"Sherlock Holmes."

Terra was startled when the man spoke. Until he introduced himself, she'd been half expecting him to be mute.

"I'm –" she began.

"American, left-handed, and far too young to be at a crime scene," interrupted Sherlock.

"…Greg, what in Hades did he just do?"

"It's all fairly obvious," replied Sherlock, looking bored. "Your accent is from the Midwestern United States. You're wearing a watch on your right wrist, and most people are more comfortable with their watch on their non-dominant arm. The time on the watch is also five hours behind, that's the east coast – probably New York, if the tall boy's keychain is anything to go off of. And your age is obvious."

"Yes, I grew up in the Midwest – Wisconsin. And yes, we came from New York. But I'm not left-handed and I'm not too young to be here," Terra responded.

"You're not left-handed?" repeated Sherlock.

Terra waved both hands in front of his face. "Ambidextrous."

"You're ambidextrous?" Sherlock said. "There's always something…"

"Sherlock, focus!" called John from the floor.

"Right," said Sherlock, turning back to the body.


"So he can basically tell a person's whole life just by looking at them?" Annabeth summarized.

"Basically," replied Lestrade.

"How?" asked Percy.

Lestrade shrugged. "If we knew, we wouldn't need him as much as we do."

Sherlock had, just a few minutes before, gone running away from the crime scene with no explanation. John had followed a few steps behind.

Terra smirked. "I'll have to test that."

"Be careful about that, Terra. We don't want him figuring out anything he shouldn't know," warned Lestrade.

"What harm could it do, really?" asked Clarisse. "Considering how much he notices, if he can't see through the Mist, I'll eat Prissy's hat."

"Why my hat?" Percy asked.

The others ignored him. Terra said, "Greg, do you really think we'll need his help to solve this?"

"Probably."

"Then he has to know what he's dealing with."

"He's a mortal!" exclaimed Nico.

"A mortal who will probably help us solve the case," responded Terra. "I know it's against the usual rules, but he needs to know."

Lestrade sighed. "You're right. I wish you weren't, but you are."

"Where do they live?"

"221b Baker Street."


"Where are we going, Sherlock?" John asked. "Do you have a lead?"

Sherlock shook his head. "Baker street. I need to think."

"Don't you usually do that at the crime scene?"

"Yes, but –" replied Sherlock, but he didn't finish the thought out loud. Something about those kids at the crime scene was off-putting to him. So many contradictions. They hadn't been in England long enough for the girl – Terra, Lestrade had called her – to change the time on her watch, but none of them had the appearance or attitude of people who'd just gotten off of a long flight. They all had a look in their eyes like they'd seen battle, but the eldest couldn't be older than 20. Not to mention the fact that they would've had to have been on the plane several hours before the police had been called.

"But what, Sherlock?"

"Nothing. We're going home."

When they reached their flat, they found two of the teem of teenagers waiting for them. Terra was sprawled on the couch and writing on her left arm with a black pen. Nico was staring blankly out the window. Both teens turned to look at them when they entered.

"What are you doing here? How did you get in?" asked John.

Terra and Nico glanced at each other. "We need to talk to you."

Terra sat up properly and clicked her pen. Nico joined her, gesturing toward the chairs opposite the couch. Sherlock and John sat down, too."

"You're helping on this case, right?" began Terra. John nodded. Terra continued, "Well there's something you should know about the victim…"

Terra launched into an explanation about some nonsense to do with the Ancient Greeks. Sherlock was listening, but barely. Most of his brain was focused on studying Terra and Nico. His eyes darted from Terra's watch to Nico's ring, then to the cramped handwriting that was now visible on both of Terra's arms, then to Nico's beat up aviator jacket, then to Terra's hair which was falling out of its neat bun, then to Nico's black CHB shirt, then to their hands resting next to each other on the couch in the few inches of open space between them.

"Sherlock, what do you think?" John inquired.

"It sounds like nonsense to me," replied the detective.

"But it isn't, Mr Holmes!" Nico said.

"I can see the look on your face, Mr Holmes. You're confused by us. We're not straightforward, like you're used to," Terra said. "Nico's jacket is authentic, but isn't beat up enough to be a hand-me-down through the proper number of generations, and it certainly hasn't had enough owners if it's in that condition. Annabeth and I are clearly close to Lestrade, but he's presumably never mentioned either of us and you can't 'deduce' the relationship between us. And then there's the getting here problem. Either we knew long before the police did that Carolina had been killed or we had a faster mode of transport than a plane. Explanations? Exactly what we've told you."

Sherlock shook his head. "Those old gods are myths. It's impossible."

"Not impossible, improbable," corrected Nico.

"It feels strange to say this to you, Mr Homes, but once you have eliminated the impossible, whatever remains – however improbable – must be the truth," added Terra. "And this is the truth, sir."

Sherlock stared at them. They were right, but… Her words were an echo of something he himself had said before, but he had never expected to hear them directed at him.

"I believe you," John told them. "Sherlock will, too, eventually."

"We ought to leave, then," Nico said, more to Terra than to John and Sherlock.

"See you later," Terra said. Nico shook both of the men's hands and the two of them stepped into the hallway. Nico took Terra's hand and they vanished into the shadows.

"His hand was freezing," observed John. "And not just how you usually have cold hands. It shouldn't be possible for his hands to be that cold. Not while he's alive, that is."

"He did claim to be the son of the god of the dead," Sherlock reminded him.

"That doesn't make him a corpse."

"Really? It sort of feels like it does sometimes," Nico said casually, walking back into the room. "Sorry, Terra left her jacket." He scooped up the black coat from the floor by the couch, waved, and stepped into the shadows again.

Of all the strange encounters Sherlock Holmes had experienced… this certainly had been one of the strangest.

"Did he do that deduction thing, like Greg told us about?" asked Percy curiously as the CHB team walked down the street, following a lead.

"Not out loud," responded Terra, "but I could tell he was trying to figure us out. His eyes were moving back and forth really fast. He looked confused."

"How did he react?" Annabeth inquired.

"Didn't believe us at first," Nico answered.

"People rarely do," said Clarisse.

"John did, though," Terra remembered. "I bet Sherlock will come around, if he hasn't already."

"How do you figure?" Clarisse asked.

Terra smirked. "For all Greg said about Sherlock not listening to 'idiots', I get the idea that despite his apparent normalness, Sherlock will listen to John."

"You think?" Nico said.

"You're still not very good at reading people who aren't dead yet," Terra commented. "The way they look at each other – I've seen that before." She glanced at the two boys on either side of her. "Actually I see it quite a lot. They rely on each other. I bet that by now John has convinced Sherlock to believe us and – "

"Sherlock says you're wrong," John said as he caught up to them, out of breath.

"What?" the two daughters of Athena said simultaneously.

"This suspect's innocent," he continued. "Sherlock says he wasn't even in London at the time of the murder." Terra raised her eyebrows. "He wants you to come with me. Said he needs to talk to you."

"So he's willing to work with us?"

"Yes."

A/N - To clarify a few things about this AU/the IU: Greg Lestrade is a son of Athena. CHB is a team of Half-Blood investigators who get involved when cases get too... Half-Blood-ey and risk exposing the continued existence of the gods to the mortals. And Terra is the main character in my novel (although the IU is obviously AU for AiNW, too. She's a regular old mortal in the novel).

Love you dearly, my nonexistent readers for this fic. Less than three!