Baldur's Gate 3's Grymforge is a fascinating location full of winding underground passages and buried secrets. The first time I played Baldur's Gate 3, I couldn't believe a massive underground complex followed the sprawling opening Wilderness area. One of the central plot threads of the Grymforge area is freeing True Soul Nere from a cave-in. There are several ways to accomplish this goal, but one of the "intended" solutions is to obtain either a Runepowder Vial or a Runepowder Barrel from a Deep Gnome named Philomeen.
Philomeen was angered by the cruel treatment of her people by the Duergar, so she stole some runepowder and fled. Normally, Philomeen threatens to blow herself and the party up using the Runepowder Barrel, and you'll be forced to talk her down. However, a sneak-inclined character can actually slip by Philomeen unnoticed and steal the barrel without her knowing.
As displayed by LifeIsCrap101 in a recent Reddit thread, Philomeen will threaten to blow up the explosive barrel but will quickly realise the party has stealthily removed it from her possession. If the party allows her to leave, she'll take her Runepowder Vial to Baldur's Gate. If you steal both the barrel...
