The Old One breathed life into the Five,
A vast world before them did thrive.
In slumber, the Old One sought respite,
While the Five clashed, locked in eternal fight.

Life they granted, life they did seize,
Within their midst, conflict never ceased.
With heavy heart, the Old One awoke,
And shattered the world, in a single stroke.

Sons and daughters untouched by the Old One's wrath,
But the vast world crumbled along the sorrowful path.

What has happened so far:

TLDR:
Five earthlings found themselves in a place called Glimmerspire. There they encountered a deathly plague. After following some clues/leads, they tracked down and dealt with the assumed source. A month passed as they acclimated, before being transported to the fortified walls of Grimwatch and the adventures that awaited them there.

Full:
Inexplicably a group of earthlings vanished from their subway car and arrived in the den of something, before exiting to realize they have no idea where they are. They observed a mounted soldier (Brened) do battle with a hairy beast, a gnoll, and slay it. After which they appear to have befriended him, somehow being able to understand a language none of them spoke. Together they made their way to the town of Redhallow, which is suffering from a flameless burning blight. Each of the earthlings has their own reason, but all have decided to try and help the people of Redhallow.

During their investigation of a couple of buildings within Redhallow, they managed to gather a small arsenal of archaic weapons and armor, along with some basic supplies. Four of the five stayed the night within the church of Helcaliant, to wake the next morning with a blessing and a brief farewell before they embarked for the mines. The fifth started for the mines that night, all alone.

Between the celestial bodies, the armored soldier, the gnoll, unfamiliar names, and now the blight, they are starting to come to strange conclusions.

The lone traveler was the first to arrive, who encountered a robed, fear-inducing individual, but was ultimately unharmed. Hours later the five were reunited as they started into the mine entrance. They found signs of bloody violence, but only one body. They also ran into small, skinny bipedal lizard-like creatures, kobolds as they would later learn. This meeting was not as friendly as some would have wanted and fights with might and magic ensued; this included even an impressively large lizard.

With freshly cooling corpses all around, a choice was made to capture instead of kill, and so, the last kobold (Khoku) was laid low and then bound. Communication proved too difficult and consultation was opted for. Prior to their departure, they met a darkly-skinned gnome (Rasmop) and her airy companion (Aerthis). She had been sent in search of the source, same as the earthlings, and finding them interesting, decided to tag along.

On the return to Redhallow, kobold, and gnome in tow, it was let slip the group's origin. The gnome called them riftlings and to their surprise, was interested and not afraid of them.

Redhallow was much the same as they had left it, with the situation only growing worse as desperation drove those still living to try anything. The reception when they returned was less warm than it could have been. Help was still offered, this time in the form of two magical elixirs that allowed one of the earthlings and the captured kobold to communicate clearly. They learned that a group of kobolds had taken up residence in the mines and they were being menaced by something that could fit the description they had already been given. Efforts were taken during this time to form a bond with the kobold.

The group met little fanfare as they departed this time and no resistance as they reentered the mines. They found most of their bloody work missing, save the ravaged remains of the large lizard. Deeper into the mines they went, entering a large natural cavern, where they encountered the group of kobolds they had been told about. After a violent greeting, the group was permitted to continue on, with Khoku parting ways.

Now they stood before a small field of not-so-dead corpses, in a widened section of a strangely worked tunnel. On their approach, part of the dead rose up. In the ensuing violence, one of the group was beaten into unconsciousness. Fearing they were being overwhelmed, they grabbed their fallen and retreated back to Redhallow, hoping to find tools to deal with this menace.

Their return was met by disheartened folk, who nonetheless supplied them with a cache of holy water. Armed for the task at hand, they trudged once more back to the mines. Something felt a bit different when they got there, but nothing disrupted them as they returned to the corpse-filled chamber. Being prepared for this threat, they dealt with it handily. It was here that Rasmop was held back by Aerthis, citing concerns over the 'Blaze'.

Unconcerned, the group pushed on, finding a large chamber with a large rock in the middle. It was surrounded by water coming from the top and covered with occult-looking symbols that no one could make real sense of. It was here too they finally encountered the rumored beast; a gnoll after closer examination. The creature fought as if on a vendetta, incapacitating one of them and nearly a second before falling itself. Its death appeared to cleanse the chamber.

Their victorious return from the mines was soured by the fact that the kobolds had attacked Redhallow in their absence. Their befriended kobold, Khoku, had aided the defenders against his own kind. The attack left some sections of the suffering town in cinders. Long awaited aid had finally arrived though, with Brened and the Baron's champion, Reynfred, at its head. Tensions were high in their first meeting due to their otherworldly origin and appropriation of equipment, which was quickly smoothed over by Governor Sendars.

Then began a time of calm for the group. Each did their own part in assisting the town to get back on their feet, while also trying to better integrate into and learn about the world they found themselves in. During this time, an emphasis was put on befriending the dwarves, given the sacrifice made by Dukhath. Khoku accompanied them in this endeavor, while Rasmop assisted in areas better suited to her ability. Not only focused on books and work, did they get to partake in the festivities of Gesphrem's night, and were also able to exchange their spoils from the mines for a modest sum. Investigating the books from their first few steps into this new world, found each in possession of a near-identical magic ring.

The peace couldn't last though. Ivirune, the Hand of the Praerius Circle had demanded answers from the group. Not all were open to her approach, with at least one openly defying her. The exchange didn't come to blows, but only just. Through a tense stand-off, limited information was shared between the different sides. It appeared enough for her to be satisfied by the ordeal while leaving the earthlings with more questions. Not eager to lose a potential fount of magical knowledge, at least one of the earthlings did their best to ingratiate themselves with the mage. That earned them promised passage, after a contentious debate.

A swift and jostling ride saw them safely to the imposing fortified walls of Grimwatch. There they were greeted by Hildemar, who cleaved them away from their guide. In a seeming effort to keep them out of her hands, the group was offered and accepted an outing to find some scouts lost in the mountains. Before entering the formidable passes, the group gained two traveling companions: Kael, a young man eager to prove himself, and Branor, an aged and experienced ranger. The group came across a partly ransacked camp with signs of a large conflict. Following one of the trails, they came upon a bloody, grizzly scene of dead scouts, with a giant at its center. The pitched confrontation was nearly lethal before the giant was slain. A trail from expected survives led deeper into the mountains...