All The Party knew of Ferrin himself is that he was a human male whom Leithe contracted to buy burger buns from, whose house seemed innocent enough in Goldvale. Ultimately they met a random transient NPC human named Darius who was hunting The Cult Of Alden and had info that Ferrin's house was a place to investigate.
(Battle At Ferrin's House)
When PCs arrived at Ferrin's House they found the front door ajar, the Darius NPC dead inside, and a cult member locked in combat with a soldier. The house was a facade for a two level dungeon1), and didn't help clear up who the supposed local Ferrin was. Above the front door was the triangle symbol known to be associated with The Cult Of Alden. After tense standoff, wherein the cultist argued that the soldier and his buddies were there to unleash things from below upon the world for their own benefit, which is arguably evil. In turn the soldier argued that the cultists were evil and this stronghold needed to be destroyed. The party sided with the soldier, murdered the cultist, and then not long after upon finding a stairway down to a second level, the soldier was killed by hostiles below before the party could progress.
Below2) in various rooms were soldiers aligned with wizards. Cultists aligned with a goblin. Everyone was holding strategic positions and taking pot shots at anyone who dared wander the hallways. PCs quickly figured this was dangerous and skirted the main combat to find several more doors, all with various beings behind them. A little paranoid experimentation of listening to doors, and having earlier found a key that fit the doors, led to the release of some creatures that were probably being held by The Cult Of Alden for blood sacrifices, although they had no way to know that was the purpose at the time.
Since the party took off rapidly they didn't know what became of the battle inside the dungeon there, but later in the day it was noted that smoke was rising from that area. Thus went the battle at Ferrin's House, which would them become thought of as “Ferrin's Ruin”. Socks & Sunny were adopted by Jules & Eyrun.
Jules, Urist, Vesper & Sirona ventured to Ferrin's Ruin3), found where the telepathic monster(Allegedly has been taken to Crompse.)) had been locked up before4), barricade gone, creature gone. They were there on rumor of there being 3 gold dragon eggs hidden here. In the chamber where the monster had been was a trap door, leading down to Level 3.
Level 3 was nothing more than tunnels going to 3 chambers. Geographically spaced out to form a triangle as a whole, and the chambers themselves all triangle shaped. This is because the triangle represents the symbol for The Cult Of Alden and “The Three”, the goblins who were Alden's bearers for the Shovel Of Alden during the time period associated with the Toc Clan Coal Mine Event. All of this happened before Goldvale existed. The dragon eggs found in this dungeon came here right after the event.
Speculatively speaking, Level 3 prior to Goldvale existing must have been a stronghold of Alden's and/or dedicated to the god Hayte. The Three chose this place to move the dragon eggs to after Alden failed to retrieve them during the Toc Clan Coal Mine Event. The three rooms here all have doors that feature the holy symbol of Hayte, which is a bloody dagger. Each room has a depression in it with magical runes that hex anyone reaching in and other abilities. The eggs were placed, one in each room, and it kept them in status. Also in each room was a table shaped alter to Hayte, designed for letting the blood of a humanoid, which channels into grooves, runs to the floor into more grooves, and leads to the depression with the eggs. The reason was to work some sort of magic to turn the gold dragon eggs into “blood dragons” for Alden's purposes.
However, with Alden apparently not around after the event, and the runes having the ability to keep the eggs in status, The Three goblins must have decided this was the best place to hide the eggs from any hostile forces of any sort. There is absolutely more to this tale and the politics of this lost time, because obviously Goldvale itself and the Goldfish Pond came into being not long after, perhaps as a supplement to this or in some other related capacity. All anyone really knows is that officially Goldvale's scenario is in place to keep the Shovel Of Alden hidden/protected, but this might be a hushed element that is every bit as important. It's all speculation at best.
The resulting fact to take away from this is that The Three are the ones who hid the gold dragon eggs here and not on behalf of the forces of Alden. The house levels would later be constructed above this site, perhaps as a disguise.