Hollis and Glimmer are able to piece together a little of the history based on the letter you found.
Illugi Swordbreaker, the Emerald Warlock, and Agera of the Shadow Face led a mercenary group called Stormcrow Company. Each had a storied adventuring background before they joined their strengths, but those stories are as nothing compared to the tales of the exploits of Stormcrow Company. The mercenaries made their base in old tunnels they
found beneath a rocky tor in the wilderness. Though Stormcrow Company was credited with cleaning the goblin tribes out of nearby hills and killing the lich who threatened the valley from its dark tower, the adventurers also accepted contracts to assassinate nobles in a neighboring city-state, kidnapped an eladrin princess in return for a ransom of questionable relics, and even burned down an entire village on a lark while passing through. In the end, they were feared more than revered.
Upon returning to town you start asking around about the whereabouts of Artem and you find that several people have seen him hurrying through the streets, bumping into people in a rush to get somewhere. You follow the stories easily and arrive at your inn. It is on fire. You find Terroth standing outside watching the blaze as the town watch is fighting the fire with many of the patrons of the tavern.
Glimmer single handedly puts out the fire (with the help of hollis in the shadows) and Terroth tells you what has happened. A person matching the description of Artem came franticly into the tavern and started a heated discussion with someone sitting at the bar. A fight broke out and a lantern was knocked over. The last thing he remembers seeing is the two men still fighting as he ran out. This story is confirmed by the other patrons. You investigate the scene and discover only one corpse, charred beyond recognition with no distinguishing marks. You do notice however that the body is much more burned then you would expect based on the fire you saw.
Finding no further information on Artem, the party travels south as indicated by the letter after Rumer arranges for a message to be sent to the town government alerting them to the location of the mountain blood.
You discovered the tor in the desert just as you expected and make your way inside.