[Edited April 25, 2023]

When the disguised demigod walked out of the blinding light, he saw the same group of teens standing in front of him. He hadn't been expecting a welcoming committee and was rather put off by all the attention. In retrospect, he should have expected this reaction-- it wasn't every day that the bat boys called in an outsider to help them do their jobs. Nightwing approached Ghost first.

"Ghost," his brother nodded to him, "we need you on another case." Nico decided to roll with the lie.

"Nightwing," he greeted, "Batman told me that you'd brief me?"

"I'll explain it on the way. We have to travel on a plane to get there. I know you don't like them, will you be ok?" The son of Hades figured that Zeus would be too caught up in whatever had locked down Olympus to bother with him. Or at least he hoped that he would be-- if not, this was going to be a very short mission.

"I'll be fine. Lead the way. We can do introductions later." Nightwing motioned for the consultant to follow him and took off at a brisk pace. Nico didn't put too much effort into keeping up. Instead, he allowed himself to fall a little behind and take in the mountain. 

He had to admit that he had been curious about where Nightwing and Red Robin spent their time when they weren't at the manor or the cave. Granted he had seen part of it in his dream, but this gave him a better picture. It was a nice base, though he would expect little else from Batman.

"Aqualad, Artemis, Kid Flash, Miss Martian, and I will head out to meet the others. The rest of you stay here and hold down the fort," Nightwing ordered, barely slowing his pace. The people he designated followed them to what Nico presumed was the landing platform. 

The demigod was confused when he didn't see a jet. Instead, there was a large red hunk of metal sitting on the landing platform. It took all he had not to gasp when that pill-shaped thing expanded into a full-sized ship. Ghost followed Dick up the ramp and onto the ship where he sat in one of the seats. Everybody else filed in and took their places. The green-skinned girl got in the pilot's seat.

It may have just been him, but Nico was shocked by the amount of technology on this ship. They had touch screens, voice-activated sensors, and it was even a telepathically operated ship. Maybe this was normal for people in the 21st century. To him, it was a bit overwhelming. He hadn't been around people who had normal childhoods. Even at Camp Half-Blood, they had limited access to technology. In truth, Nico wouldn't have known what was normal or not.

Once they were in the air, the briefing began, "Ok, Ghost. We are headed out to a crime scene where we need you to determine the cause of the death of some scientists. They had been working on a cure for some type of new poison. We believe that-- in order to keep the scientists from concocting an antidote-- someone had them killed. " Dick explained. Nico had never been involved in such an elaborate investigation before and he had to admit that it gave him a fair share of adrenaline.

"And we know they weren't killed by poison because...?" Nico started. He needed all of the information in order to create a clear picture of what had happened to the scientists.

"The poison causes people to bleed from the eyes and nose. The victims didn't show either symptom and chemical analysis of their saliva and blood show that no suspicious substances were in their system at the time of death."

"I see. Anything else I should know, going in?"

"No, we have a large team out in the field already so the scene has been secured. You shouldn't have any... distractions."

"We'll see about that." The consultant muttered under his breath. He was no longer in Gotham, monsters were a much bigger threat now. The gods never really visited Gotham, so there weren't many demigods there to attract monsters. Out here it was a different story. He would consider a monster attack to be a pretty big distraction. Nico saw many of the other team members exchange confused looks.

It wasn't long before they reached the island where the lab was. It was small, but could still hide an entire laboratory with ease in the dense forest. Miss Martian landed the ship in a clearing that was filled with tall grass and the group of uniformed teens cautiously off-loaded. They were greeted by the Wonder Woman girl and the girl who looked like a bee.

 Dick and the two girls exchanged a short greeting before Dick introduced Nico. The group was led into the nearby building and through the halls toward the place where the bodies lay. Ghost had analyzed the halls for clues as they passed, but all he noticed was that they were strangely clean. Like they had just been mopped or something. Like hospital floors, Nico wrinkled his nose at the thought.

They finally came to a dead-end hallway where the other group of heroes that he had seen before was gathered. They all came to varying forms of attention or readiness as their group approached. Nico spotted Tim at the front of the group.

"Red Robin, show Ghost to the bodies and assist him in any way you can. The rest of you will brief us on what exactly happened here." Nightwing took over.

Tim led his brother through some double doors into a laboratory. Inside were two dead bodies, sprawled out on the floor. Nico surveyed the room briefly, looking for hints. The lab seemed to be used for chemical testing of some sort. There were bottles of weird liquids in a clear-doored refrigerator behind him. There was one of those stainless steel metal lab tables with wheels in the center of the room.

"Have any luminol?" Ghost directed towards Red Robin. Bruce had been giving him lessons in forensic science for weeks now and it was all starting to pay off. Nico had insisted that he didn't need to know how to properly work a crime scene because he could speak to the dead, but now he was eating those words.

"Don't you?" Tim teased.

"Stuffs expensive," Nico shrugged.

The vigilante pulled a small spray bottle and a black light out of a black case and handed it over. Nico gently misted the floor around the bodies as Tim turned out the lights. Nico shined the black lights over the floor and came up with smears of glowing substances that could have been a number of different substances. He took a picture with a camera he had found in the black case for documentation. 

Luminol would only illuminate the smears for about 30 seconds so he wasted no time. Ghost leaned down to the floor and cautiously smelled the smear and got a nose full of chlorine-- possibly from a cleaning agent like bleach. The liquid in question wasn't urine. Urine plus bleach made a toxic gas that was deadly if you inhaled too much of it. A professional wouldn't risk it.

"This area has been cleaned recently. Likely hiding the blood," Ghost noted aloud.

"If that were the case, then why would they leave the bodies? Unless... it wasn't the victim's blood," Tim reasoned. Ghost hummed in agreement, stepping over the first corpse. Tim turned the lights back on.

On the table was a rolled-up towel, which Nico documented with the camera. It occurred to him that that would be a pretty good place to hide something. It looked unassuming and discarded-- unimportant-- but looks could be deceiving. Nico carefully made his way across the room towards it. He didn't want to walk over any important evidence. If this was used to clean up the evidence, there was still a chance that they could salvage some DNA from it.

By now, the team that had flown here with him was coming into the room. They spread out along the wall and stayed out of the demigod's way, which was appreciated. Nico was still an ADHD teenager and he did not need them distracting him or disturbing any evidence. Nico carefully unwrapped the towel, which was dry to the touch. This meant that it likely hadn't been used to clean up any liquids recently. There was nothing on it except a bit of blood. Two thin pale streaks, to be exact. He assumed this was the rag with the victim's blood that Tim had mentioned earlier.

That was suspicious. You'd have lost more blood from a nosebleed or even picking off a scab. Plus, there was no blood visible on the bodies. Nico paused to think for a moment. What did he know?

First of all, Tim had said that they found no signs of a struggle. That ruled out anything to do with blunt-force trauma and meant that the scientists had likely been taken by surprise. Maybe they had even known their attackers or the killers had disguised themselves.

"How did they gain entry to this room?" Ghost directed this question to Red Robin again, presuming that he would have the most detailed knowledge of the scene.

"They used a keycard. They stole it off of one of the other scientists who reported it missing this morning. We believe that they were killed sometime last night when the keycard was last used. It had to have happened before the card went missing. The company policy is to deactivate any cards that get lost so that people can't gain access to this building." Ghost nodded along in understanding.

So they knew how the men had gotten inside the building, but they still weren't sure about the cause of death. There was no blood so no major entry wounds, so where had the blood come from? Was it the killer's or the victim's? If one of the victims scratched their attacker, they would bleed. However, they would more likely hold the towel to the wound, causing a blood spot, not a streak. Plus, they wouldn't leave their own DNA behind. Not if they were as professional as he suspected they were.

He moved to check under the victim's fingernails just to be sure. Both the victims had been wearing gloves, meaning they couldn't have, realistically, scratched their killers. But then why was there cleaner on the floor? Nico picked up the luminol spray and Nightwing got the lights again. Ghost sprayed the luminol on the scientist's gloved hands and found that the older man had a substance on his gloves that was probably bleach like what he found on the floor. It was likely that the man had cleaned the floor himself and not the killers. So this piece of evidence was irrelevant. Nico took a picture anyway, just in case more evidence came up later.

If the blood on the towel wasn't the killer's then it must have been the victim's, as Red Robin had guessed. What could be used to kill someone almost bloodlessly? More importantly, was the murder weapon still in the lab? Most of the chemicals here cause people to foam at the mouth, bleeding from the nose, or other noticeable deaths. Tim would have checked for that already but the son of Hades decided to ask anyway.

"We're sure that none of these chemicals got to them?"

"Yes. We did a field analysis on their saliva, a bit low-tech, but accurate. None of the chemicals here were ingested." That certainly narrowed down the list, though there was still the possibility that something had gotten into their bodies using a different method.

"What are your deductions?" Nightwing asked, having come up behind his younger brother without him noticing.

"Well, I've ruled out most of the usual causes of death in violent crimes. Whoever did this was obviously a professional. I've found the victim's blood on the towel."

"How do you know that it was the victim's blood?" Asked some kid with green skin. He seemed young, a naive kid like he used to be. Nico humored him and answered the question.

"A professional killer would know better than leave any of their own DNA behind," the consultant replied.

"Oh." Came the soft response.

Nico began looking over the counter to maybe see something useful. In the sink, there was a handful of syringes. This in itself wasn't all that suspicious considering the types of experiments these men were doing. What caught his attention, however, was that only two of them had water inside of them and that the sink itself was bone dry. Ghost carefully lifted one of the two up, looking carefully at the substance inside. It looked just like water. There was no water in the bottom of the sink or on the faucet head.

Nico pulled out the plunger and carefully smelled the contents. Just as he thought, it wasn't water in the syringes, but hydrogen peroxide. Having formulated a theory, he went back to the bodies and spent the next 15 minutes examining every inch of their upper body. At one point Ghost had to take off one of the victim's shirts. It was then that he found his entry wounds. It was small and perfectly circular. If you weren't looking for a needle entry, you probably would have missed it. The injection had been made directly into his jugular, but it had been so far down on his neck that it had been covered up by his turtleneck. Seriously, who wore turtlenecks anymore?

"I've got it," Nico reported, standing.

"No way, if the proteges of Batman couldn't figure it out, how could you?" A girl wearing a green bra thingy and cargo pants, Artemis he thought her name was, sassed.

"Let's just say I'm good friends with death," Nico smirked at his own joke. He actually hung out with Death quite a lot. These people didn't seem to find him quite so funny.

"So, you have a conclusion?" Nightwing prompted.

"Yes, these men were injected with hydrogen peroxide. The bubbles that the hydrogen released in their veins caused their heart to stop. Your heart can't pump air or hydrogen. They could have done the same thing by injecting regular air into their bloodstream," Nico explained. Artemis wrinkled her nose and a couple of others looked uncomfortable, but there wasn't anything strange about that.

"Good work," Nightwing nodded.

"In your opinion, was this a professional hit?" Nico almost frowned. He knew Tim would have come to the same conclusion he had by this point. Maybe this was just for the benefit of the team.

"I would say so but this job is strange. People usually only use the peroxide in the bloodstream method when they're trying to replicate a heart attack. There's no way they could pass this off as a heart attack. Peroxide isn't instant and it would have given the scientists enough time to raise the alarm after they had been attacked. A professional would have known that." Tim crossed his arms and Nico got the distinct feeling that he was impressed.

"So, what are you thinking?" Nightwing pressed.

"I think that it was set up to look like a professional hit. To what end, I'm not sure. No professional would bother with the peroxide when plain air would work the same way. It's an unnecessary step and it leaves behind a residue. And they wouldn't risk the scientists alerting the rest of the building. It's sloppy." Ghost accepted two white sheets from Nightwing and began laying them over the bodies. He'd seen everything he needed and wanted to show the dead some respect.

"You seem to know a lot about the ways of professional hitmen." The one called Artemis pointed out. Nico eyed her wearily. He didn't like what she was implying but didn't dignify her thinly veiled accusation with a nasty response.

"That's why I'm here, isn't it?" He returned simply. Artemis pursed her lips.

 "We'll include your conclusion in our reports and I'll let you know if the tox screens confirm your conclusion," Nightwing said as he began to head out of the room. The son of Hades followed him along with the rest of the team. Nico knew that Nightwing was giving him a hard time just to make it look good for the team. They boarded our separate modes of transportation and headed back to the base. Nico should have expected the in-flight interrogation.

"So, how do you know so much about death?" Kid Flash pressed. His question, unlike Artemis' seemed to be out of genuine curiosity. Nico eyed him uncomfortably. He didn't really want to get into his past with these people.

"I have always been good with death. It helped that my father and I had similar interests. I was able to pick up the tricks of the trade before he died," the demigod answered vaguely. 

"Was your father a hitman?" Artemis frowned.

"No, but I can see why you would think that," Nico replied easily. He had probably made it sound like that with his vague description.

"So what did your father do for a living?" Kid Flash spoke up again.

"I don't like this line of questioning. Let's just say he was in the death business and leave it at that, ok?" It wasn't a question and the cabin lapsed into awkward silence as they settled in for the rest of the flight. Nico wasn't the best with living people, he'd rather deal with the dead any day of the week.

Once they had landed, they were greeted by the big bat himself. Ghost approached him first, unafraid. He guessed it surprised his temporary teammates at how comfortable he was around the Caped Crusader. Oops. Nico decided to ignore it unless someone asked him about it. It was better to pretend nothing was wrong than to make a big deal out of it.

"Ghost," he greeted. He used the typical Batman voice.

"Batman. It would have been nice to know where I was going before you chucked me into a nasty old telephone booth," Ghost chastised, of course, but the veteran vigilante didn't respond.

"What was your verdict?"

"Death by hydrogen peroxide injection. Made to look like a professional hit. Do I get to know why someone wanted those poor souls dead?" Batman glared at the demigod, "Didn't think so."

"Go back to Gotham. Here, that compensation we agreed on." Batman tossed him a pouch. Nico was confused, he hadn't talked about any pay. The look Bruce gave him said to go with it so he did.

"You paid him for that?" Artemis cried out.

"A guy's got to make a living somehow. Doing favors for free leaves you hungry," Nico said as he tied the pouch to his belt. Batman gave his newest protege an approving glance.

"So you just go around determining the cause of death at random crime scenes for money?  How do we know you didn't drop those bodies for us to find and say it was made to look professional to misdirect us?" Artemis crossed her arms.

"You have a wild imagination," Nico returned.

"You aren't denying it," She pointed out.

"I wasn't aware I had to. Do you really think that Batman would put me on this job if he thought I killed someone? His no-kill rule is legendary," Nico pointed out.

"Enough. Aqualad, take him to the zeta tube. The rest of you will complete your mission reports," Batman ordered. The dark-skinned boy with gills and webbed hands led him back to the weird light teleporter thing.

"Thank you for your help, I apologize for the rest of the team," Kaldur said, he sounded very diplomatic.

"It's alright, not very many people appreciate my skill set." Kaldur hesitated for a moment, looking uncomfortable

"Sorry to pry, but just how much did Batman pay you?" Nico opened the pouch and smiled. He was curious as well and he reached his hand down into the bag. Ghost smirked as he pulled out one of Alfred's famous chocolate chip cookies, "Shhh, don't tell Artemis." He grinned slyly. Kaldur's face was priceless.

"Go in peace, friend." The son of Hades smiled at the odd dismissal and stepped through the tube. Nico walked out into the Batcave, where Alfred was waiting on him. Nico held up the cookie triumphantly for him to see.

Alfred gave the boy a small smile, "Mission accomplished, I see."

"Yup," Nico took a bite of the cookie, "and totally worth it." He didn't know how they compared to Sally's blue cookies, but they were delicious to him.

It was about half an hour later when Nightwing and Red Robin came back to the cave. Bruce had come back a while earlier and had started training him in hand-to-hand combat. The demigod still had a lot of room for improvement but he could hold his own in a fight. Nico was advancing faster in training than the other boys had, but he credited that to the fact that he was half-god. He had a huge advantage with his heightened senses and demigod powers. Nico was learning to hone his senses more than he had ever been taught at camp. It was hard, but it was rewarding.

"Hey! Nico!" Dick called after he had changed into his civilian clothes. Bruce stopped the fight as his oldest approached.

"Yeah?" the son of Hades asked, getting a drink from his water bottle.

"What was up with you and Artemis?"

"I don't know, she was being kind of pushy and I got annoyed." Dick chuckled quietly.

"You didn't exactly make a good first impression."

"Well, It's not my fault that my existence seems to be the problem. I didn't even say anything mean. And making it look like I took money didn't help," Nico pointed out.

"What was really in that pouch?" Tim asked, having finally changed as well.

"One of Alfred's cookies," Tim smirked in amusement.

"We'll work on your people skills later," Dick said, about to head up to the manor.

"Or we could just not," Nico replied.

"What do you mean? You need to know how to be diplomatic," Tim started, about to go off on a tangent, he was sure.

"Yeah I know," Nico interrupted, "I just mean that I might be better if I didn't get friendly with your team. The less they know about me, the better."

"I see your point. We'll figure that all out later. Right now I'm hungry and, if my watch isn't on the wrong time, dinner should be soon." With that, they all headed upstairs as a family to dig into some of Alfred's cooking.

++++

The conversation was limited at dinner, most of them just dug in. It had been a long day for all of them. Bruce told them about an off-world mission that he would have to take part in for a short while. During his absence, they would be staying at their individual team headquarters. Normally, they'd stay with Alfred, but he had some ill family in England to attend to. This meant that they would all be relocating this week.

Nico would be going with Dick and Tim to the mountain under the cover of needing protection. He wasn't quite looking forward to it, but he wasn't necessarily dreading it either; it would give him a chance to examine different fighting styles and catch up on the schoolwork that he had been procrastinating on. He was interested to see what special abilities Dick's teammates had. Very few of them looked human. Not even Batgirl, who was a confirmed human.

Nico packed a week's worth of regular clothes and non-descript t-shirts so that they wouldn't recognize his style. He would sadly have to leave his aviator jacket at the manor for the time being. Nico packed a few pairs of sweatpants, a hoodie, some black skinny jeans that sort of fit, and his converse. Along with all of that, he packed his weapons, uniform, and godly supplies. Always be prepared.

He also warned Annabeth that nobody was supposed to contact him unless he contacted them first. The last thing he needed is for this team to decide he was a threat and interrogate him due to an IM. Artemis was already suspicious of him and he didn't want the rest of them to hate him as well. Nico didn't really care, but it would make things easier if they liked him.

The son of Hades packed and left his bag by the door so he could grab it in the morning. Alfred was leaving early tomorrow morning. Bruce would be leaving around noon, so the rest of them would head to their separate headquarters or safe houses soon after Bruce left. It would just be for one week, so Nico wasn't all that concerned. Though, a lot can happen in a week. Nico wasn't sure what to expect from this week at the Mountain, but he knew it wouldn't be boring.