Like most of his cousins, Harry Potter was content with his lot in life. Mostly. If he could foist the Duchy off on Sylvia, the elder of his Potter cousins, he would be much happier. It would mean he could devote his entire self to being the Captain of Blackstrike. Unfortunately, his father was the current heir, and was able to do both, so his grandparents saw no reason why he couldn't unless he became completely obsessed with Strike and one of the girls just became his steward or something.

Since that was actually what Harry wanted (to spend the rest of his life cracking codes and hunting horribles) he was aiming to make it clear from the very beginning. Which is why, Invisibility Cloak and Marauders' Map in hand, he searched his trunk for that potion Sylvia had slipped him earlier.

The Onaxia potion was a creation of his mothers'. It silenced scent and breathing, sharpened reflexes and senses, and it had saved many lives. Technically speaking, he wasn't supposed to be taking it yet, as repeated exposure on adolescents hadn't been tested, but Sylvia and Aaliyah had tinkered with it as one of their home study potions projects. While this version, Onaxia-beta, wouldn't sharpen his reflexes, sight or taste, it would sharpen his hearing, muffle his breathing and silence his scent.

Considering Aaliyah, Sylvia and the diluted potion were the only reason he could use Onaxia at all, he was grateful. Onaxia was difficult to use if you hadn't experienced the affects before, but Onaxia-beta had made it easier to train them all to use Onaxia, and in the off chance they needed it, each of the Blacks had an Unbreakable vial on a chain around their necks. Which could only be done because they'd trained on the Onaxia-beta.

Swallowing, Harry capped the vial, stuffing it into the bottom of his trunk with a mental note to send it home. Wrapping himself in the Invisibility Cloak (his father and grandfathers') he plucked the map from is bed, slipping his wand into the holster on his wrist.

Ron faced him from his bed, where he sat cross-legged, a mirror twin to the one in Harry's pocket held by relaxed fingers. A chessboard rested in front of him, Septimus Weasley's chessmen facing off against a set from a Christmas cracker they'd broken together two years ago.

Nodding solemnly at his clansman, Harry flipped up his hood and waited in the Common room until Percy, who had told him with a wink that he was on Prefect duty tonight, exited the Portrait hole. Carefully, hand on his wand, map in hand (thank you, Fred and George) he made his way to the Third Floor corridor, hissing out a breath as he peered in the keyhole. Fishing an Extendable Imager out of his pocket, Harry nudged the enchanted wooden snake into the keyhole. It slithered in, returning a few minutes later and falling limply into his hands.

Stealthily, Harry slipped back to where Percy was, mumbling the incantation to close the map and revealing himself to his cousin only long enough to toss the older boy one of the food parcels Iliana had pressed on him earlier that day. It was really just a palm-sized leather purse, but if he knew Lia, she'd had her Mum or Dad enchant the purses with Undetectable Extension Charms, and stuffed them to the brim after a visit to the kitchens. Both boys ate in silence, returning to Gryffindor Tower when Percy's shift was over.

When he arrived back in his dormitory, Ron looked up, now engrossed in what looked like Quidditch through the Ages (but that Harry was pretty sure the cover was Transfigured or Illusioned to disguise one of Ron's weird strategy books). Nodding to his other cousin, Harry took out a parchment (which had been enchanted, like many others, with several Charms including Protean) and scribbled

Information found. Meeting tomorrow after dinner, usual place.

Yawning, Harry retired to his bed, anticipating the reactions at the Meet tomorrow.

TESSELLATUS

The Hogwarts Black contingent gathered in a formerly-collapsed tunnel the twins had found and Percy had excavated last year, in preparation for having their Lady and Captain come to Hogwarts. Instead of being an open access tunnel, it had been password sealed. Now, in order to get into the well lit room behind a mirror on the fifth floor, you had to trace the right rune in the right place.

Except, well, it wasn't a Rune. Percy had simplified the characters in 'Kuro' the Japanese word for Black (and the only other country where they had a large presence) and keyed the spell to that. Their parents had gamely Transfigured and shrunk couches and tables, which Percy had restored to the appropriate size, and they could call their house elves to bring them food.

When Harry arrived, it was find Percy and Ron puzzling over an Occlumency text, the twins over maps of Hogsmeade and it's surrounding lands, and Draco scribbling a letter. Iliana and Daniella were sulking in a corner together, Sylvia was making notes in her Healing Journal, and Aaliyah and Blaise were hunched over their Potions textbook, muttering together. Rolling his eyes, Harry dropped in place and called

"Sari, can you bring me a snack?" Sari, Sasha's daughter, popped in, heard his request, and nodded. Popping out briefly, she came back with a generous tray of treats and a crate of pumpkin juice.

Slurping from the bottle and gaining annoyed looks from his cousins, Harry pulled out the Extendable Imager and tossed it to Percy, who set it up to project on the wall. All the Black cousins hissed or growled when they saw a trapped Cerberus. Living with Sirius Black and Remus Lupin for any length of time made it hard not to hate being trapped, and especially for someone or something that doesn't deserve it. Seeing as the Blacks congregated for the summer every year, they had seen the aftermath of full moons, even after the introduction of Wolfsbane.

Lip curling, Percy asked sardonically

"What's the plan, Captain?" Fists bunching, Harry growled

"Research. Prepare." Iliana, who'd looked up at the Cerberus, cautioned

"You can't be obvious about this. Strike is meant to be a shadow organization, not the Auror Corps." Nodding, Harry chewed his lip and decided

"Silver, take point on research, since Percy has OWLs. Run your conclusions and proof by him when he's not busy." Eyes hard, both nodded.

"Raido, as my tactician, I need plans to take it down and keep it down. Collaborate with Silver on Cerberus research, and then consult Team Terror on how they can help you. If you can find spells, run them by Percy." Ron and the twins agreed, all smirking when Harry continued

"Aaliyah, Dani, I need you to research Potions and Healing. We're not going into this blind. Lia, Draco, Blaise, I'll need you to collaborate with me on information control. The less people who know what we're up to, the better." Draco nodded, and Blaise replied

"Understood." Clearing his throat, Harry gave the traditional final order

"Keep me updated. Operation Cerberus is a go."

TESSELLATUS

Later that night, Harry wrote his first actual report, coded as a letter to his cousin (and current commander) Aquila Abbot.

Cousin Aquila,

As you've probably heard, we've settled in at Hogwarts. Did you know the Third Floor corridor is out of bounds? We were discussing reasons why, and Raido suggested it might be a trapped Cerberus. I told him he was being ridiculous, why would they keep a Cerberus in Hogwarts?

Then he said that Hogwarts doesn't always make sense, and that was the most nonsensical explanation he could think of. I told him he was off his rocker and to go study or something. Lia yelled at me for that, but it was worth it.

All that aside, we're looking for the things you told us to.

Love,

Harry

Aquila received the report while he sat at his desk in the Strike base office. Frowning, he yelled for his cryptographer, Kuroo Azusa. Shorter than her older cousin Akira, she still had the crazy Kuroo hair and wore it banded back by a strip of white cloth. Hurrying in on the whisper of the shifting of heavy silk, she rounded his desk to read over his shoulder.

"Clumsily done, but sufficient for his age group." Azusa's confirmation sunk a rock in Aquila's gut. His cousins, in proximity of a trapped Cerberus? His cryptographer continued, delicately gentle hand on his shoulder

"If he follows the pattern- Ron studying takedown tactics, Sylvia and Percy are investigating, the twins will consult, and Dani and Ali are collaborating on Potions and Healing." Huffing, Aquila reminded her

"That means Iliana, Draco and Blaise, and probably Harry too, are on information control." She nodded, smoothing his equally black but slightly tamer hair before replying

"They survived a troll, together, if Iliana's report is correct. They won't be stupid about this." He sighed and muttered sulkily

"I wish we hadn't had to teach them this."