The dwarven merchant Gundren Rockseeker hired three adventurers, the hunter Kell, traveler Milo, and investigator Bildar to escort a wagon of supplies to the small mining town of Phandalin. There, he and his brothers had made a big discovery and in his haste he and his bodyguard, Sildar Hallwinter went ahead of the party. Also along for the ride was a friend of Gundren, an elf named Lithil who claimed to be a noble heritage.
After a few days travel the party were ambushed by goblins while investigating the dead horses that Gundren and Sildar had been riding. Following a trail used by the goblins they discovered Cragmaw Cavern, a hideout for the local Cragmaw goblins. There, they found Sildar a captive of the goblin Yeemik, who agreed to release the human in exchange for the party eliminating Klarg, the bugbear in command of the cave. They were successful, and the goblin upheld his end of the deal after taking a share of Klarg's loot.
In Phandalin, Sildar revealed he was an agent for the Lord's Alliance, a group of allied political powers in the region. His organization had a dual agenda in sending him there. The Rockseeker brothers believed they had located Wave Echo Cave, a long lost mine of great mineral wealth. As well another agent of the Lord's Alliance named Iarno Albrek had been sent to Phandalin a few months previously and they had lost contact with him for a worrying amount of time. He warned the party that Gundren and his map locating Wave Echo Cave had been sent to a place called Cragmaw Castle, which Sildar had no knowledge of. They had done so on orders of an individual called the Black Spider.
In Phandalin each member of the party followed their own agenda for a time. Bildar had come to the town after hearing of investigation job, and met the elf Sister Garaele, priestess of Avandra, who wanted him to seek the advice of a banshee for the location of a lost spellbook. Milo was drawn to town by his dreams, where his archfey patron had sent him images of Phandalin, and destroyed castle, and a desecrated shrine. Lithil was in a fact an assassin with a group called the Red Arrow. She met with with her contractor, Halia Thornton, who wanted her to kill the leader of the local bandit gang, the Redbrands. And Kell came to town looking for revenge, after previously being attacked and nearly killed by the Redbrands and their leader, Glasstaff.
At a taphouse frequented by Redbrand brigands the party met a dwarf cleric of Pelor named Agnus Tectite, who had also come to town to rid it of the Redbrands. Despite the protestations of the Townmaster, the Redbrands had taken control of the town and were extorting and bullying the citizens. After a confrontation the party decided to head to the ruined Tresendar Manor, the cellars of which had been converted into the Redbrands base.
There the party rescued a family taken family by the bandits and encountered a crazed creature known as a Nothic, seemingly convincing it to turn on the Redbrands. Investigating a rudimentary wizard's workshop they unknowingly alerted Glasstaff via his rat familiar. Escaping via a secret door, he ordered the Nothic to devour the adventurers, who meanwhile encountered drunken brigands and a trio of bugbears bullying a pathetic goblin. A fierce encounter ended with a number of enemy corpses, and a new ally in the form of the goblin Droop. But the party were knocked unconscious after Milo detonated a gnomish puzzle box Lithil had been trying to solve, collapsing the manor in the process.
A letter left behind by Glasstaff delivered two revelations; the wizard was in fact the missing Iarno Albrek, and he too had been working for the enigmatic Black Spider. Sildar had received word from a halfling in town that the druid Reidoth was the best source for information on the region, and encouraged the party to find him in the ruins of Thundertree. The small town, located in the northern Neverwinter Woods, had been destroyed twenty years ago by the eruption of Mount Hotenow, and was the druid's last known location. The party also accepted two other requests in town. A retired adventurer asked them to investigate reports of undead near a place called Old Owl Well, and the townmaster Harbin Wester begged them to deal with orcs sighted near the local landmark Wyvern Tor.
Lithil reported her failure to kill Glasstaff to Halia, who seemed more concerned with the elimination fo the Redbrands and collecting any of the wizard's correspondence. She and Milo also declined offers to join an organization called the Zhentarim, while meanwhile Agnus, Kell, and Bildar were offered positions in the Lord's Alliance by Sildar if they could aid him in securing Wave Echo Cave for the Rockseekers. Milo also performed a ritual shown to him in his dreams, and gained a familiar in the form of a psuedodragon named Philip.
At Thundertree the party struggled with ash zombies, the remains of citizens killed by the eruption of Mount Hotenow, and twig blights, vampiric plants arisen in response to the tragedy. They found the fortified building housing Reidoth, who revealed he was observing the prescense of a young green dragon named Venomfang that had made its liar in a destroyed tower in the village. He was also concerned by the arrival of folks in black masks and cloaks skulking around the village. In return for the location of Wave Echo Cave the party agreed to chase Venomfang away from the ruins.
By waiting for the dragon to return from hunting they enacted a plan to ensare the dragon with Lithil's druid magic and forced the beast to flee in face of a coordinated assault. The unknown individuals had been watching the battle, though, and ambushed the party. They were in fact members of the Cult of the Dragon and had been seeking to treat with the dragon. The party defeated the cultists in combat, and though the leader failed to fly away with the use of a potion, the final living cultist escaped his bonds in a moment of inattentiveness by the group.
With Reidoth's guidance the party located Cragmaw Castle, where Lithil volunteered to stealthily investigate in animal form. Unfortunately the druid was caught by the combination of a collapsing rubble trap and locked doors. The goblins took her to their leader, the bugbear King Grol. Grol was attending to two other visitors; what seemed to be a female drow, and Iarno Albrek. Lithil witnessed the drow's appearance change to match her own before being knocked unconscious.
Just as the party began to worry, Lithil returned with the most direct path through the ruined castle towards Gundren. Entering stealthily the party avoided the goblins guarding the entrance, but were ambushed by a strange creature known as a Grick in a ruined chapel shrouded in darkness. In the room to the north they found a trio of goblins praying at a desecrated shrine of Ioun, now dedicated to the goblin god Maglubiyet. Recognizing the shrine from his dreams, Milo followed the death of the goblins with the destruction of the shrine, revealing an odd stone within, which he claimed.
Arriving at the throne room they found King Grol, Iarno Albrek, and their prisoner Gundren Rockseeker. Combat erupted, but the betrayl of Lithil, in fact a doppleganger named Vyerith, led to the defeat of the party. Lithil, though, managed to escape her bonds and using her wild shape ability escaped with castle with Bildar and Milo. With Droop's help they reentered combat, killing Grol and capturing Glasstaff. Vyerith escaped with the map, however, and before doing so killed Gundren. The party returned to the castle one last time after resting to eliminate the remaining goblins and obtain Gundren's corpse, but in the process Milo released an owlbear the Cragmaw clan had kept imprisoned and found a scroll of revivify in the process.
After burying their fallen friend the party returned to Phandalin with Iarno in tow. Their Sildar called the various leading figures in town together for a meeting, revealing the threat posed by the Black Spider. Within Wave Echo Cave was the Forge of Spells, with legend said could be used to create items of magical power. With it and the metals mined from the cave the Black Spider could threaten the entire region. The various figures in attendance, most of whom were in fact agents of various organizations in the region, agreed to trust the party to find the Black Spider and end the danger he posed. But first, they asked them to ease the townspeople's fears after sightings of orcs mere miles from the settlement.
Near the small village of Conyberry the party located the banshee Agatha, who they bartered with in return with the information Garaele sought. They learned the spellbook of the wizard Bowgentle had been traded to a necromancer named Tsernoth from the city Iriaebor more than a century ago. At Old Owl Well they coincidentally met another necromancer, the foreign wizard Hamun Kost. He suppressed his undead minons to chat with the party, claiming to be in the area for research purposes. After eliminating the orc band at Wyvern Tor the party convinced Kost to depart the area as soon as he completed his research. After arriving back in town Sildar agreed to accompany the party to Wave Echo Cave, while Sister Garael offered Bildar and Milo membership with the elusive Harpers.
Reidoth then led the party to Wave Echo Cave. Upon entering they found the corpse of the Tharden Rockseeker, slain by the Black Spider and his minions. While exploring the cavern they fought a number of skeletons and zombies, the remains of the orcs, dwarves, and gnomes that had fought to the death their centuries ago. It was in an encounter with a number of ghouls that Sildar was slain. When Agnus used the scroll of revivfy to revive him, he disappeared in a flash of radiant energy.
The parties hardships only increased in the smelter cave, where a flameskull stood guard over what they thought was the Forge of Spells. After one massive blast of fire most of the party was nearly defeated, but Kell leapt into battle, giving them time to recover and regroup. The ranger gave his life to create an opening for the party to destroy the undead abomination. To their fortune the cave had a soulcore within it, a mineral that absorbed souls when they were released from fallen bodies. Using the smelter they melted down the core, and Kell's soul returned to his body.
Venturing onwards the party found a small workshop housing a brazier with eerie green flames dancing within. It was the Forge of Spells, but also there was its guardian, a otherworldly being known as a spectator. The creature had gone made from isolation, believing the mine was still in operation despite the constant assaults of undead on the workshop. The party managed to convince the spectator its obligation was completed, and in doing so freed the aberration from its madness. It left on friendly terms with the party, who claimed the few remaining magic items left in the workshop. After studying the Forge they determined it had lost most of its power over the years, but could still be used to temporarily enhance their equipment. Milo, acting on a temptation planted within him by his archfey, placed his strange ore in the Forge of Spells. The stone bloomed into the shape of a flower, releasing an energy that almost seemed to be shaped like a skull.
To the south they discovered a chamber with a ceiling of glittering minerals, and the destroyed quarters inhabited by the wraith Mormesk, a wizard who died defending the mines. After offering the creature a magical scroll and revealing they had, in a sense, defeated the spectator the wraith gave them most of its treasure from life.
As they explored the final sections of the cave they found a group of bugbears excavating the area by what seemed to be a drow. After defeating the goblinoids and slaying the supposed drow, discovered instead another doppleganger, they discovered a small temple to Moradin, where they were assaulted by cluster of giant spiders. Soon after the Black Spider himself, a true drow named Nezznar, and the doppleganger Vyerith ambushed the party. After a pitched party Vyerith and the spiders were slain, the Black Spider was captured, and the final Rockseeker brother, Nundro, was rescued.
Returning to Phadalin they celebrated their success, with the townspeople declaring they always had a place their, even offering to gift them the land the remains of Tresendar Manor stood on. Nundro gave the party a stake in the Wave Echo Cave mine once it was opened, and Sildar intended for Iarno and Nezznar to be tried to their crimes in Neverwinter. Instead, though, Halia Thornton freed the pair from their cells and the three disappeared into the night. At Reidoth and Nundro's request the party helped destroy Mormesk and obtain a symbol of a poisnous spore that had overtaken a section of Wave Echo Cave.
Back in Phandalin Milo and Kell chased Philip into the wilderness, where he led them to meeting with Milo's patron, the Rose Queen. Also there was a sallow-skinned man named Anton, who's soul had been released by the stone Milo had thrown into the Forge of Spells. The Rose Queen promoted Milo's rank among her follower before then turning her attention to Kell. She offered the ranger a deal; he would complete one task of the Rose Queen's choosing when she desired it, and in return she would free his father, who had been cursed and transformed into a tree. Kell, with some reluctance, accepted the deal and was informed the archfey had left her mark on Kell's father, insuring no woodsmen would attempt to cut him down in tree form as long as they recognized her blessing.
At last, as Sildar departed for Waterdeep, the party rode with Nundro back to Neverwinter, in the same wagon in which they had left it.