From the introduction:
Centuries ago, the great 'War of the Ancestors' seemed destined never to end. Perhaps it wouldn't have without the archmage Vricad, who devised a plan to trap the souls of legendary heroes in Stones of Power, and use these to power his ultimate weapon. He trapped the soul of the legendary bard Securis in a topaz, creating the Stone of Imagination. The soul of Jon the Brilliant, in an emerald, became the Stone of Mind. The soul of Jim Faindel the Vibrant, in a sunstone, became the Stone of Life. The soul of the legendary warrior Lady Khelbiros, trapped in iron, became the Stone of Might. There were two others, but their names have been forgotten.
With all six stones, Vricad created a living construct, which thanks to the stones could shape destiny. Vricad wanted the war over, so his weapon triggered one large, magical explosion, reshaping reality. Thousands of people were erased from existence, among them Vricad and others contributing to the war. The weapon deemed this necessary for the war to end, as its creator demanded. The world was left in ruin following the long conflict's resolution, and the Stones of Power, propelled to different corners of the world by the explosion, were forgotten by most people.
Vricad Marsh, named after the man whose weapon was triggered in its center, is the lone reminder of the war. Being the epicenter of the world-altering explosion has locally warped reality in this harsh, swampy terrain, and few people dare to explore it.
One person who did, was Doctor Haezad, a slightly insane surgeon with a rare specialty in meta-surgery (the art of operating on the soul), which is widely considered either immoral or a scam. The disdain of his peers drives Haezad to want to prove the usefulness of meta-surgery. His research into souls led him to the story of the Stones of Power. Over time, the doctor was able to acquire three of them: The Stone of Life, the Stone of Mind, and the Stone of Imagination, though the latter has broken since the war. Part of Securis' soul escaped, rendering the topaz non-functional.
Using the stones, Haezad reached the center of Vricad Marsh and found the remains of the ultimate construct. The surgeon was able to stitch Vricad's weapon back together, though it can only reach its full might with all stones. Thus, Haezad and his underling Rhac have come to the city of Nanmur to acquire the Stone of Might. Additionally, the legendary songstress Mara makes her home here. Haezad wants to repair the Stone of Imagination by replacing the escaped parts of the legendary bard's soul with a part of Mara's. Fortunately for him, there is a worrisome darkness inside of Mara's soul, so she actually agreed to let the meta-surgeon operate on her. Haezad promised to remove the darkness, but instead took the part of her soul related to her imagination...and for the songstress that part contained her voice. She has been mute ever since. Haezad needs to meta-surgically splice that part of Mara's soul to Securis' soul to repair the Stone of Imagination and has returned to Vricad Marsh to do so, while Rhac is supposed to steal the Stone of Might.