A swamp plague

[alhoon]

Here is the idea I got from Lesser Evil. This is in Generic D&D world.

There's always been a revulsion for insects and bugs as carriers of disease. Mosquitoes are known for carrying a host of dangerous diseases- malaria. etc. What if they carried some sort of zombie plague?

In the villages around the swamp more and more people seem to be suffering from a curse that warps their minds and behavior.
- At first they start becoming more absent minded and forget things
- Then their attitude starts changing in subtle ways. They become more submissive but they have bursts of bad mood and anger
- They start having hallucinations and delusions and speak revelation some times with fear other times about "them" and the swamp.
- They disappear in the night. If constantly watch they seem to suddenly try to leave.

The malady/curse strangely seems to affect only adults.

What's behind that?

A mind flayer Nurisher has been sent to test a new technique. The mind flayers have biologically/psionically bred a kind of musquito that carries a special psionic malady and want to test it.
The disease makes the afflicted more prone to psionic and psychological influence and control. On the final stage the disease gives a compulsion to the victim to leave and try to join a "superior" creature. Charmed agents of the mind flayer in the area tell the victim to head to the swamps to meet superior creatures (it is the "them" part).
Other thralls of the mind flayer take whoever reaches the swamp to the mind flayer that sends them to his sunless citadel.

PS. The technique has only partial success. 1st it doesn't work without side-effects (drives people mad) and 2nd the mind flayer is able to catch about 1/4 people that try to reach him since they die in the swamps.

[The Lesser Evil]

If the plot has proved to be a partial success, perhaps the "superior creature" part is subject to interpretation and can vary, ie. not limited to mind flayers. Perhaps some other force has gotten wind of this and has been intercepting the diseased victims claiming to be the superior forces. A clutch of neogi or a beholder might work, or maybe a rival clan of mind flayers. Necromancers could be killing the defenseless people in order to build an army of zombies. Some evil druids might know about this and are ruthlessly killing the victims as they try to maintain the natural balance of power. What did you plan on killing the missing victims?

[alhoon]

Since it is generic D&D for 8th-9th level it is ... trolls eating up the villagers. The chieftains of the local tribes of trolls are charmed by the mind flayer but the trolls eat more people than they surrender to their chieftain and to the mind flayer. Also an evil cleric and a necromancer work alongside him as lieutenants. The necromancer is charmed but she doesn't animate dead as the mind flayers consider them a threat and an abomination. The cleric actually does this to destroy civilization (philosophy similar with the voodan in the DT&DLs).

And a problem presented that I haven't anticipated (but it was welcomed so I rolled by it) was that the PCs have caught a ranger charmed and infected. Since they defeated him, he considers them superior creatures... so he spills out everything he knows . Since my PCs have hit a dead end in their investigations, the few things the ranger knows are enough to motivate them and hopefully locate the mind flayer.

BTW they have 5 more days... after that, the mind flayer will pack his 4-5 captives and leave, taking with him the notes about the experiment and whatever thralls (necromancer, cleric) survive. That will leave the PCs with a great problem to deal with musquitoes without any "help" from the mind flayer or his notes.

[The Lesser Evil]

Is it possible to cure the plague with a remove disease spell? Perhaps to remove the disease a healer has to make a caster level check like the plague was a creature with spell resistance.

How would the party be able to deal with the mosquitoes?

[alhoon]

Is it possible to cure the plague with a remove disease spell?

Yes, with rules like the mummy rot cure. Remove disease against a caster level check DC 15+1/stage of the disease.

How would the party be able to deal with the mosquitoes?

Good question, but this is their problem.
Although, they decided to ask a high level Druid for suggestions (an 8th-9th level elf druid that lives in the swamps) so it will soon be my problem.
I'll make a short adventure the journey to the elf, and he will probably ask them to fetch him a few things to make a ritual that will soften the disease and also to come up with the herbs needed for the cure.

They have taken too long, the mind flayer left, so there will be no clean solution. The villages around the swamp will be plagued with a disease that turns people temporarily crazy and sends them looking for a superior creature.
Still, the villages won't need to be abandoned. The cure will be turned far less contageous and it would have a reasonable chance to be cured without magic. The area will be considered a madland from there on, but there will be far less fatalities. A few people (from around 2000 people living in 9 villages) will get sick every month, and once a while somebody will be lost by the disease, but it will be as much a problem as all the other diseases around a swamp.

It makes the area special in a way IMO. Soon, after the initial shock and the grief for the 30-40 people already lost in the swamps pass, people will adjust to the new malady, will thank the PCs about their help and start making jokes about the situation.
I plan to throw a few things in the future in faraway taverns like:

"Lord Fregin has gone crazy, he was passing through the swampy area on the north. People there say there is a disease that does this. Thankfully he will recover the rumors say." etc

Reminds the PCs that this is an interactive world