Alone in the desert is not some place you want to find yourself as a PC. A plume of smoke stretched across the sky for several miles. Enemies and lurking monsters would be coming to explore the wreckage within hours no doubt- it was unsafe to stay put. The PCs set out to head toward the mountains east of where they were.
They happened upon an old village in dire need. Many townsfolk were already sick with the poisoned water plague. Their skin was turning as a lepers would. They had days, maybe even hours, before they turned into lumbering zombies- shells of their former selves. Local Karrnath guards were rounding up the townsfolk into cattle cars and taking them away. The town made one last stand holding off the guards from across the river, but their waning strength would lose the battle shortly. The town mayors wife asked the PCs for help as she was now acting on behalf of the town due to her husband falling just days before.
The PCs snuck into the guard’s outpost killing them one by one and releasing the townsfolk. After getting some information from the guard foreman, they were headed further east toward into the mountains to where supplies were coming from. There they found a secret hole into the mountainside leading them deep underneath the mountain. They found themselves observing a long deserted kingdom. Sporous molds popped regularly polluting the air. The PCs investigated the main hall to find out more about this ancient kingdom. They found it was an old dwarven city led by a great dwarven caster by the name of Nagash. In the old historical journals they uncovered that he had suddenly gone crazy. He trusted no one and began secret and unsavory activities against his family and kinsmen. He took up botany and his gardens overflowed with plants which seemed to have taken to some unnatural intelligence. Then, one day, the journal stops, and no more passages are written. The king himself sat with his crown and magnificent maul. The PCs looted the gear and uncovered a portal.
After activating the portal, they realized the kingdom war far from abandoned. Groans of lumbering plants moved on them as the portal began its slow process of opening. They fought off their foe escaping into the portal. They had yet again found themselves in another unknown place, this time much colder than before as they appeared in a cave with a raging storm outside.
Taking some cover, the PCs had the unfortunate experience of realizing they were not alone in the cave as a group of Orcs were taking cover in the same cave. While the Orcs proved to be horribly racist against both Dwarf and Elf which rubbed the PCs the wrong way in some exciting banter they agreed to band together to get through the mountains. Through discussion, they discovered that they were in the now in the northern section of Khorvaire in the mountain borderlands of the Eldeen Reaches. The Orcs were looking to call upon other Orc tribes as well as the elves (pre-erata for 5e shifter race). Demon had been running in droves in the land tearing apart the tribes. The only way to kill them was to band together and mount a coordinated assault. The PCs were now under severe time constraints to get out of the mountains and coordinate an alliance with unfriendly tribes against a common demon threat.
The exploration of the mountains was grueling. Cold exhaustion seeped into their bones and froze them to their core. Getting off of the mountain was impossible as they traversed razor thin switchbacks across the mountain range. Storms picked up out of nowhere slamming them with wind and snow trapping them in an old abandoned signal tower for an eventful night of hellish torment as demons tracked the PCs to their cabin of short lived refuge.
Maps used during part 2 of the campaign: