Faced with the Phyrexian invasion, the planeswalker Teferi decided to save his people instead of staying to fight, "phasing out" parts of Jamuraa and Shiv. When Teferi returns to Dominaria, he finds an embattled, desolate world on the brink of ruin. Centuries have passed since the calamitous Phyrexian Invasion and the rise of Karona. Although things did improve immediately after Karona's destruction, it's gone sharply downhill ever since. The connection between the land and mana has been badly damaged by the multiple cataclysms. This mana drought has decimated the population and desiccated most of the plants and animals. Civilizations and cities have given way to small enclaves of huddled, desperate survivors. Almost nothing thrives in this harsh landscape, where salt storms flay flesh from bone and destroy what few meager crops manage to grow. Never has daily life on Dominaria been quite this desperate.
Teferi begins to blame himself, and planeswalkers like him, for this sad turn of events, but he has little time for guilt. The fabric of space and time has also been seriously damaged. The damage first started with the Brother's War, and all the misfortunes since then, have made things worse. This instability spreads across many worlds and affects many planes, but it harms Dominaria the most. There, reality itself has shattered, creating time rifts that cause Dominaria's past to collapse into its present, haphazardly bringing people, places, objects, and monsters into being. It is the finishing stroke for a wounded and dying world, unless Teferi and his allies find a way to heal the damage before it's too late.
With his knowledge and power, there is still hope, but he can't do it alone. Teferi is joined by many familiar faces, such as his old friend Jhoira, and a few new allies, such Venser, a talented Urborg artificer who's managed to learn much about machines and Dominaria, despite his humble beginnings. They'll have to take very serious action if they want to set things right. But when the situation is this dire, extreme action needs to be taken. If not, Dominaria is doomed to extinction.