A preface to this before I tell you. That story was meant to be vague, because your people did not get a good look at the situation before they had to retreat. But I'll explain it to you OOC.
I guess we did our best, though I am a bit confused about those barricades; did the undead attack the barricaded houses from within/below?
Also, what types of undead were there - just the animated skeletons, or also some classical ghouls and zombies and maybe a few more intricate anatomical constructions? And how massive is massive? Are we talking thousands or more?
The people within the barricades were demons. They did not know they were demons, so they barricaded themselves in, but little did they know their souls had already been devoured. So they morphed into their actual demon form and broke out of the barricades to attack the troops. Please note that Malthen knows nothing of this OOC - for all they know, something attacked the people within the homes. But the odd circumstances would lead some to believe otherwise. Malthen's troops are not idiots.
The monsters that emerged from the barricades are a special kind of creature that I made up. I am still thinking up more detailed anatomy, but basically it is a type of grotesque demon. There are various sub-species of this one type of creature, but the anatomical differences between the sub-species are somewhat minimal. Maybe, one type of the creature is very large and fat and blundering, but severely strong, while others are smaller but more agile.
I am actually in the works of creating several of my own types of creatures, this is just one of them. I will explain why, but this knowledge is all OOC.
Basically, a portal has been opened to somewhere.

That is all the information I can give right now. The actual kingdom within your borders is rather safe at this point, so don't worry too much. You held your ground as much as possible amidst chaos. As for the amount of skeletons, you don't know for sure, but appearing in the town... maybe 500 or so? The are rather weak, though. Its the other monsters you should worry about, and there are maybe 100 of those.
The presence of the skeletons and the appearance of demons are, actually, contrary to what you all may think, quite unrelated. It is
not a portal to "hell" (there is no hell in Sekai, first of all... maybe at most an underworld of sorts where necromancy originated [necromancy is, bringing the dead alive and discovering a way to cheat death - demons are unrelated to this practice], but things are not nearly as black and white in this world). Please note: If "hell" is ever mentioned in this NES, as in the line "What the hell?" or any reference to hell as a location, it simply means the Underworld. Hell is slang for Underworld, but Sekai's Underworld is far different than any typical Christian view of hell in our real world. And no I am not ripping off Diablo. What these "demons" are is much, much different. Sekai's underworld is not hell. Bad people do not go there when they die. Demons do not come from there. It is a magical region, so to speak, in which necromancy came to be and a few gods used as a playground. I have more information on this, but, like I said, it is completely unrelated to the demons or the matters at hand. So, I have gone way off-topic at this point. Oops.
EDIT: kkmo, as you might have noticed if you looked in the Vacation thread, I will be gone for most of July. I hope there won't be any problems with NPCing the Malthen Kingdom; I intend to provide some reasonably extensive instructions, and possibly a detailed write up of the kingdom (politics, personalia, social structure, culture, etc. - I've been making them semi-intentionally confusing up until now) for your modding and story purposes.
Yes, and I will be gone half of July, more or less - but I'll have Internet access through a lot of this post-July 7. You leave the 3rd, your post said, and I leave today, so I guess we will chat again when you return from your trip (archaeological practice... sounds interesting Indy

). Feel free to PM me all of that stuff you just mentioned, or post it in this thread or the other thread (if its IC). Any of these options are fine. I will take good care of Malthen, and I mean that in the least sinister way possible.