Having not really delved into many magic-related mods (other than Mystcraft, arguably) - I'm playing on an FTB Infinity server, a friend and I have set up a small base on an island...and I keep hearing worrying sound and musical cues every so often (not just the midnight/dawn/midday/dusk ones). I seem to recall that some old version of Thaumcraft (possibly) had a mechanic whereby if you mistakenly set up shop in a chunk with one of those evil-looking obelisks near it, your area could invisibly get more and more dangerous (due to a buildup of vis? I can't recall) until eventually lots of nasty stuff started spawning. Is that still a thing, and if so how do I make sure we're not camped on top of Minecraft's equivalent of the Hellmouth?
tl;dr - how do I make sure my FTB Infinity base isn't going to suffer an unforeseen magical death in the future?
Well, I tend to play with music off so I don't know about musical cues, and the only annoying noises I get are the usual 'cave noises'. But to reassure you about Thaumcraft, here are the ways that some of the nodes will try to kill you;
- Sinister nodes - most commonly found in obelisks, barrow hills, and eldritch altars, but can randomly be other nodes too - will convert the area around them into an 'Eerie' biome, easily visible on the minimap once it's spread (as it turns all the grass dark grey), and if you're close (spawner range) to them at night they can spawn Furious Zombies, which are exactly like Angry Zombies except they have tons of health and get bigger as they take damage. If you're camped next to one you'll know about it pretty much straightaway once night falls.
- Tainted nodes - will spread taint around them. These seem to be fairly rare, and taint spread does seem to be limited by default in Infinity, so unless the biome type changes to Tainted Lands, or you start having huge purple tentacles appear close by, you're probably okay.
- Hungry nodes - if you try to camp near one of these you and your camp (and your inventory) will end up in the node.
- Warp - not a node type, but Thaumcraft's warp effects will only affect you if you actually start to accumulate warp, through research or other means (for instance if you really want a bunch of temporary warp you can eat Zombie Brains... but I wouldn't recommend it unless you have a really good reason) - be careful though if you ever do Research Sharing with others as that might also give you all the warp from their research.
So it's probably not Thaumcraft trying to kill you. Yet. Maybe later.