Book: The Downfall of Molaesmyr
Molaesmyr, the City of Wonders, was the greatest and stunningly beautiful city of all the settlements that survived the Calamity. Its architects and builders were master artisans, its craftsmen were creating wonders on a daily basis, and its scholars were considered the learned elite of Wildemount. They gathered insight into historical mysteries, pre- and post-Calamity religious aspects of life and arcana, and into their own origins. In their research they dived deep into the history of the Veluthil Forest and the Emerald Sanctuary.
They sent out search parties and archaeologists throughout the forest, hunting for hints of the reasons why the Arch-Heart and the Wild-Mother would team up during the Calamity, endangering their own lives and the rest of creation itself, in order to protect a small stretch of forest for over a 100 years while the rest of the Veluthil Forest burned to the ground around it.
For a long time they found nothing, looking only above the ground and amongst the flora and fauna around them, but at last they found what they were looking for deep, deep under the city of Molaesmyr. They first happened upon the opening leading downwards by discovering the remains of some Age of Arcanum labyrinth, finding a immeasurably large complex of caves made of stone and covered in a bark-like wooden texture. They started exploring the complex and found this wooden material increasingly becoming the main material and primary component of the walls around them.
Scholars and Arcanists experimented with the wood and found it to be extremely vital, highly resistant to most sources of magic and elements (but highly vulnerable to fire) and excessively regenerative. They dug into their history and past and found that their pre-divergence ancestors had not only known about this material, they had even named it: Lignum Vitae. They had known that this wood grew only on a very specific tree in all of Exandria, the Tree of Life, Avendesora.
According to myth and folklore, Avendesora grows downward into the earth, its roots drinking water and air and sunlight while looking like gnarly, branch-less trees with an arcane halo set on its highest point. According to legend, its crown is cradling the heart of the planet.
At first, the scholars were hesitant to use any of the seemingly holy material. However, when a sickness started to spread during a particularly harsh winter the herbologists used lignum vitae for medicinal remedies to heal the sick. Soon after, other scholars started experimenting with the different aspects of the wood, first using it carefully for either medicine, alchemy, chemistry or arcana. As nothing dire seemed to happen, they started combining these aspects and researching ways to weaponize the saplings and resin of Avendesora.
It was then, that disaster struck the city. The city of Molaesmyr and all its inhabitants were eradicated in mere minutes, the surrounding area struck by an arcane plague and the Veluthil Forest was turned into a cursed abomination full of mutations and stalking nightmares.
Those of the people of Molaesmyr who survived left the Veluthil Forest and renamed it "Savalirwood" for the elven word "savalir", meaning "guilt".