So...update.
The fortress has been thriving. The King has arrived and was installed in his opulent throne room, and I created a new 10-man militia squad (apart from the original team of 5). The main idea was to have a force stationary who could defend any incoming attacks from below, as I was about to dig deeper for precious minerals and magma. The original 5-man legendary squad could then hold the top and, if necessary, run down the stairs while the new squad kept any intruders at bay.
As you dig deeper you typically will stumble upon huge underground caverns, full of plant growth, minerals, underground trees (yes, they exist), things like cave spider webs which can be used to make silk and, of course, dangerous beasts.
The cavern I had breached didn't seem too dangerous in terms of regular critters (animals, cave humanoids) but it wasn't long before a giant eyeles dinosaur Forgotten Beast showed up. I walled it out before it could reach my guys, and left it to roam around for ages while I trained some more. I was digging down along a shaft I created, ever deeper, hoping to find magma and other useful or precious stuff.
At around level -130 I strike semi-molten rock! I carve out a room and start making preparations, I cut open the wall and discover the huge underground Magma Sea.
I then flooded the lower reaches of my stairwell TWICE with magma, once severely burning a miner and the other time almost trapping my chief medical dwarf in a slowly filling room of magma death.
He got out in time tho, since magma moves relatively slow. Clearly I had to be more careful. I backtraced my steps to the 'highest' (ie not too deep) magma reaches so I could actually mine it from above and judge the danger/risks properly before diving in there and digging out walls. After some trial and error I managed to cut out a huge room around a uppermost layer of the magma sea. Now I need to make sure I don't a) fuck up some crazy magma experiment and b)keep watch for any magma creatures to pop out (if at all).
I immediately started building a few magma-fueld workshops and furnaces down there. Up until now I've had to work with coals of all kinds, which is a pain since they are rare to make and require a production process of their own (you can for example put a guy on wood-burning dutes, which will produce charcoal. But that burns through a lot of wood very fast, and it's not always easy to come by). Not so with the magma furnaces...they are infinitely powered by the magma below them.
As I was cutting out some debris, one of my miners strikes a strange blue mineral ore...ADAMANTINE!!! OH GOD YES!
To be clear, adamantine is the most valuable, strongest, sharpest and most lightweight of all ores in DF. It's rare and is only found in veins near the magma sea, making it really hard to mine. Somehow I found a relatively upper later, since there is no magma near to it (yet). I've mined a 30-40 blocks but I stopped there - before I can make some 'magma safe' doors to block off a potential magma flood from flooding my new furnaces I shouldn't keep digging. (magma safe items are made from materials that have a higher melting point than the heat of magma, there are only a handful of stones and metals that qualify). I produced two adamantine battle axes already. More stuff to follow.
I also managed to build a magma-safe pump and install it above the magma sea. As it was finished, I called a pump operator in there to start it...hilarity ensued. It would appear that I had underestimated the speed with which the magma would be pumped up.
I flooded like half the room with magma before barely being able to turn off the pump (brave pump operator!). It was only a single floor layer so it dried pretty quickly, but if he hadn't been able to go in and turn it off I'd have been in a really shitty position again. So we're not touching the pump until I figure out what I want to do.
Let's hope some dwarf doesn't go insane and start pulling levers and activating machines.
In the meantime I'd let the Forgotten Beast in that was wandering around and told you about the epic fight (see above post), but I didn't say everything.
I 'forgot' to mention that the reason the first squad couldn't hurt it for ages was because I'd equipped them with fucking empty crossbows. They were using them to bash the Beast over and over again, hahahah. Most of them became legendary hammer users after those days and days of melee figthing with an empty crossbow tho! So at least SOME good came of it.
Mental note: manually pick militia weapons next time...and pay attention while doing so.
I'm also suffering from a population explosion of kids. Almost half of my fortress is kids and babies, my dwarves are breeding like SHIT. Since they're fairly useless until they grow up and have a tendency to get themselves hurt (and hence make their parents upset) they're kind of a pain. I may just gather them all up in a room and drown it with magma for laughs.
But I think that might cause a fatal spiral of berserking and melancholy parents. Mm. Oh and if I DO manage to make a system to get that magma topside, I'm totally still building that golden tower. With magma shooting from it, down on Elven and Human carvans.
P.S. My hospital has one permanent resident: a dwarven child with a permanent spine injury.
He's a paraplegic, basically. Adult dwarves can learn how to use crutches to get around ('crutch walking' is an actual skill), but it appears children don't. There were actually 2 paraplegic children -both danger room accidents - but one was brutally murdered in his bed by ANOTHER dwarven child who had gone into a berserk rage because he felt his wounds weren't tended to in time.