The Origin of the Slith
A faction side quest offered by Kasparov after Dangerous Curiosity is complete and Devil's Crossing reputation reaches Honored. Travel to Hargate's Isle and recover Hargate's Formula from the depths of the laboratory.
The boat is not inside the hub. Cross the bridge from Devil's Crossing into Lower Crossing, turn left, and follow the western shoreline north. You can visit the island early, but the abandoned house's trap door stays locked until this quest is accepted.
- 1Meet the prerequisites and speak to Kasparov
- ▸Complete Kasparov's side quest Dangerous Curiosity first.
- ▸Raise Devil's Crossing reputation to rank 3, Honored, or higher.
- ▸Speak to Kasparov in his detached workshop at Devil's Crossing and accept the request to recover Hargate's research.
- 2Take the Lower Crossing boat to the island
- ▸Cross the eastern bridge from Devil's Crossing into Lower Crossing.
- ▸Turn left after the bridge and follow the western waterline north.
- ▸Interact with the Row Boat on the shore to travel to Hargate's Isle.
- 3Enter Hargate's Laboratory through the abandoned house
- ▸Go to the abandoned house on the north side of the island and descend through its floor trap door into Hargate's Laboratory.
- ▸If it remains locked, verify that The Origin of the Slith is present in your quest log.
- ▸The laboratory combines cold and acid/poison enemies with green damaging ground that resistances do not mitigate; keep moving and pull enemies onto safe ground.
- 4Defeat Ellena and recover the Formula
- ▸Proceed to the end of the laboratory's second floor and defeat the area boss Ellena, the First Slith.
- ▸Open the Ornate Strongbox in Ellena's room and recover Hargate's Formula.
- ▸Ellena can drop her unique monster-infrequent necklace, Ellena's Necklace.
- 5Choose whether to give the Formula to Kasparov
- ▸Return to Devil's Crossing and report to Kasparov.
- ▸Giving him the Formula unlocks the Act 6 follow-up Kasparov's Gamble.
- ▸Keeping the Formula unlocks the Act 6 follow-up Hargate's Mysteries.
- ▸Both choices grant XP and a random Relic Blueprint; only handing it over also grants Iron.
If the quest is unavailable, verify Dangerous Curiosity is complete and Devil's Crossing reputation is Honored. If you cannot find the island, turn left immediately after the eastern bridge and follow the shore north. If the trap door is locked, confirm you accepted this quest from Kasparov.