About 1,500 years past, some Rock Monsters (see description) opened a dimensional pathway from their previous spot in this universe to this spot—the valley. They travelled through the Elemental Plane of Earth, thus bringing in some of the weaker denizens of that plane. Their odd method of travelling (see description) set up a dimensional shock which turned all in the area to stone—even the stone!
After the main invasion, occasionally some other Rock Monsters will make the trip. When this happens, someone near the valley might turn to stone. This has happened in Ashton about ten times in the past 900 years of the villa’s history (although they no longer remember most of them!). There is, however, no danger of the entire world turning to stone. Eventually (another thousand years or so), the Rock Monsters will get tired of the area, leaving of their own accord to another solar system at least 10 light years away. A few, of course, will stay behind—the ones set in their ways.
If the party communicates with the Rock Monsters in a sufficiently nice and dignified manner they may be able to persuade them to stay out of a small (15 ft) ‘path’ straight through the valley. If the problem is presented as beyond mercantile—for example, the stoning of townspeople—the Rock Monsters might think of leaving. They will only (and can only!) do so if the party provides some help. The party must either provide knowledge of another suitable planet in this solar system (only Mars or Titan, but be careful if you have them inhabited!) in which case the Monsters can divert their path, or the party must be able to make a path themselves, to another solar system (not necessarily through the Plane of Earth—when the Rock Monsters get there, they can hook up).
Even if the Rock Monsters are taken care of, however, there are other monsters which must be taken care of to make the valley safe: the Green/Brown Dragon, the Spiders, Basilisks, Cyclops, and about the number of wandering monsters listed on the table (they can be between 3/5 and 1/1 of the total number, with at least one of everything killed except the Living Hole). This number does not indicate how many there are, just how many must be taken care of before the general ‘path’ is safe.
Clues to the problem of the Rock Monsters may be found in various places. One such is the Temporary Stronghold, for an M-U who came (about 1,500 years ago) to study the area immediately after it was turned to stone. Unfortunately, both he and his assistants turned to stone because of subsequent ‘immigrations’.
A powerful and extremely dangerous clue is the Potion of Time Travel* in the Lair of the Giant Spiders. When first quaffed, it will, due to the planar imbalance, send the drinker to just before the ‘invasion’. Due to the fact that he is not of that time, he will be allowed a normal save, but if not made, he will be stone. Assuming he makes the save, he will then see a brilliant flash of light, then many dark balls coming out of the sky. There is a 40% chance he must save vs. Death or be hit, taking 8-48 points of damage (or half if another save vs. Death is not missed) because one lands on him. A second draught of the potion will (50%) return him to normal time, or (50%), return him to normal time +1-4 weeks.
