Right
The academy didn't spend very much time going into inner village politics and history. The assumption, she figured, was that clan children who needed to know that information would be taught by the family, and the civilian-born ninja trainees didn't really need to know that information. What information on the founding there was, was fairly prefunctory and whitewashed, and history more than a hundred or so years pre-founding was so mythologized it was practically nonexistent. A bit of culture shock, coming from the well documented world she had, that even the private Uchiha archives she had access to only partly sated.
But even the very low-depth Academy lecture was able to impress something on the students present for it. Her clan, the Uchiha Clan, was old. Very, very old - as a group, it had existed for much, much longer than the organized village system in general and Konoha in particular. And being so storied, and so tied to the founding of Konoha, it had been granted certain privileges that only the Senju shared.
Priviledges like the room she was in now, and the rest of the extensive tunnel network that underlied the entire complex. It was a statement of trust, and a statement of power - trust, that Konoha had allowed the founding clans free access to entrench themselves into the very grounds of the fledgling village without undue scrutiny, and power, that the clans could make use of those networks to their best advantage in case of warfare or invasion, using their experience with the passages to great effect.
Both the trust, and the power, had died. The Uchiha clan numbered only single digits, now, even if you were inclined to include the rogues, and Hisana had little doubt that both ANBU and Root had tried to map the tunnels out following the attempted coup - as best they could, anyhow, considering how many of the defenses were tied to the Sharingan. Kakashi and Danzo had to have limits on their time, surely?
And so this was the decision she needed to make: in the case of an invasion, the Uchiha clan no longer had the manpower to secure their district's underground themselves, and yet, they (she) had never officially transferred that responsibility onto the overall village government. Yet.
It should have been an obvious choice. And yet.
And yet.
For the past few years, she'd tried to minimize the amount of direction her edicts really put on the clan's future. She'd make the common-sense decisions that maintained influence, certainly, but... This wasn't- this wasn't really her inheritance. By rights, Sasuke's place in the line of succession was so much higher than a clan outcast that it made her head spin, and... Mary Kingston was even less of an Uchiha than Hisana was.
She'd taken things over because Sasuke couldn't, but she'd always thought (expected) that would be a temporary arrangement. She'd taken the diction lessons and bought a few higher quality kimonos, and it was all just putting on a mask. And yet... years had gone by.
And now she was standing under the Naka shrine, considering her options. This information wouldn't stay with just Konoha's official groups - ROOT would snatch up any plans in an instant, and giving Danzo the blueprints to crawl around under her feet was a disturbing thought. If he shared it with his buddy, Orochimaru, it could easily make the eventual invasion worse, not better.
But then, on the other hand, Danzo knew far too many secrets of the Sharingan for her to imagine he had never been down here. Bypassing defenses keyed to those eyes would be trivial for him. And if she really wanted the Uchiha to make a clean break with their sordid past...
She looked up at the tablet, the vast majority of its contents still obscured to her still incomplete Sharingan, and her grimace spoke volumes. This tablet, this shrine, this secret meeting room... it all had to go. The inscription had been modified to bring grief by the servant of Kaguya, and that's precisely what it had done - to everyone that had read it. She didn't remember the exact phrasing of what was hidden from her, but that didn't matter - she knew the generalities, and the actual truth behind the words besides. If it wasn't for concern over Sasuke's reaction to losing their heritage, she'd have destroyed it herself long ago. As it was, if it disappeared into a Leaf vault somewhere, she wouldn't shed any tears.
There had been no official map of the tunnels, when she had first gone looking for it - when the district was being rebuilt, she'd had to look for potential tunnels beneath new foundations herself, much of the time. The architectural maps she had now were still quite possibly incomplete, and she had little idea how they compared to what village intelligence had dug up themselves. But just the trust that it would show in the village leadership to hand that over, and ask for their help... she hoped it was the right decision.
She hoped there was a right decision.
AN: Intentionally written to be somewhat ambiguous on when this took place, but I really do think that Hisana would have done something with the Naka tablet at some point.