This mission is strange. When I first booted it up, I genuinely wondered if I had found some hidden gem, a diamond in the rough that had flown under everyones radar. There was no information online I could find, and the first area, the fort, was actually rather fun...

Then, as I descended into the depths, so did the missions quality.

The worst part of Down in the bonehoard was most definitely the burrick caverns... So this mission decides to copy that section, and completely ignore the larger chambers; just row upon row of brown corridor with no end in sight.

Oh, and in the watery part, lets add a death pit where they can break the fourth wall and thank some of the community. Cool little historical detail for me now, terrible mission design.

Eventually, you make your way through that into the treasury itself. A mess of underground rooms. Slightly easier to navigate than the tower of illusion, or oblivion, but that's not saying a lot.
Honestly the treasury is... just strange. It's a maze of boxy rooms, despite being hammerite, I didn't see a chapel or a factory down there; It feels more like a large underground survival bunker. It's also crawling with guards, both hammerite and regular. gameplay is dull, and there is nothing to look at.

Apparantly france exists according to the insistance this mission has that golden bottles are french brandy. Which really primes you for the fact that the writing is not good. It's very much predictable and does not follow thief lore. It also doesn't do enough to make me respect it's lore as it's own thing.

There is some kind of combination needed to open the vault at the end, but you can brute force it with a few quicksaves, which is what I did. That vault then contains pretty much the entire haul the mission has. So really the only objective is: Break into the vault.

Ultimately, this is a terrible mission. It tries to do too much, doesn't make much sense doing it, and just... doesn't work.