While on your way to find explosives to get True Soul Nere out of a cave-in at Grymforge, one of the options leads you to a Deep Gnome named Philomeen.
Philomeen seems to have a special kind of explosive as this seems to be like Smokepowder but with a twist, something more potent, stronger than other explosives.
The thing is, confronting Philomeen will either get you blown up or result in her just giving you a vile of this powerful stuff but there is a way for you to get it from her.
How To Get Runepowder Vial?
Obtaining the Runepowder Vial is the easiest among the options you have when it comes to getting explosives at Grymforge.
All you need to do is make yourself known by approaching Philomeen and once you pass an Ability Check, you may get on her good side.
She will tell you that you can have a vile from her explosive powder, which is revealed to be a barrel full of Runepowder. (This can be used to destroy the cave-in)
How To Steal Runepowder Barrel?
If you have tried to take the Runepowder Barrel during your dialogue with Philomeen, you may have ended up seeing how explosive it can be. (She ends up blowing up the whole area)
Taking this requires that you are not only sneaky, but you also need to be a bit strategic since attempting to simply steal the barrel will cause you to go around.
To steal the Runepowder Barrel, you need to hide and sneak up to it to move it out of the way and this will lead to a cutscene.
The cutscene will later end with Philomeen seeing no other options but to leave, which she does instead of attempting to help the other Dark Gnomes.
How To Get Both Explosives?
This one can be a bit tricky because you will want to secure the Runepowder Barrel first and knock out or kill Philomeen to get the vial from her inventory.
Something similar may be done by accepting the vial and stealing the barrel from her afterward but this can be dangerous as she tends to blow it up.
The trick to getting both the Runepowder Barrel and vial is to quickly act when it comes to stealing them or killing Philomeen.
Verdict
Players who want to be on the good side of the story will often just leave with the vial and this is indeed enough to get rid of the cave in.
If you plan to use the Runepowder Barrel for something more dramatic, taking it and keeping it for later may prove useful.
Should you decide to spare Philomeen, you will be able to encounter her in Act III, where she has even more Runepowder Barrels nearby.