"Warpstone, by any other name, will mutate just the same."
- Unattributed author, 1999 I.C.
Wyrdstone, that precious resource of supposedly miraculous properties, is more commonly known as warpstone elsewhere in our Empire and other parts of the civilized world. I would normally recommend any traveler who journeys into the ruins of Mordheim to beware, as while some less than savory folk in our land place a high value on this substance, those who know its real value are willing to kill for it.
Warpstone is solidified magic, vomited forth from the great gate in the far north. As with all things magical, contact with it should be kept to a minimum. Handling warpstone directly is not recommended, as it can cause burns, lesions, and other disorders of the body upon physical contact. Identifying warpstone is usually an easy enough matter, as the substance glows with the same ill-fated and baleful light as the moon Morrslieb. If you must handle warpstone, keep contact brief; perhaps use a smith's tongs or transport it in a chest, packed with sand or leaded glass.
The nature of warpstone itself is one of the closely guarded secrets of our kind. Knowledge of the stone, and its nature and properties, is certain to attract suspicion. As the event sin Mordheim have certainly drawn the attention of the Witch Hunters or other orders of the Temple of Sigmar, I recommend caution in any chance encounters upon the road. Lest our conversations become a matter of public record, I urge you to burn these letters and the attached maps and charts once you have committed them to memory, or transcribed them with the proper ciphers.
Above all else, you must secure a satisfactory supply for our ongoing efforts. Mercenaries and other seekers of fortune likely care more about the promise of gold, than who is buying their sword-arm. Any expenses above and beyond what we have discussed will be compensated upon successful completion of the assignment.
Make haste! The rat-men have been troubling my dreams again, and I fear their tunnels may have already reached the city. The eyes, they are always watching me, even the face of Morrslieb seems to mock our plans, leering at me every night through my bedroom window!