The Blasphemy quest is one of the most impactful in Blood of Dawnwalker's prologue, since it impacts the Blood Mass at the end of the day. When you find Gremla, bemoaning the theft of her tapestry, she explains that she took on that task of weaving a vampiric banner for the Knyaz, and that Brencis won't be pleased if she can't get it back.
It's easy enough to see the writing on the wall as to the outcome for not completing this one. However, the quest's second section, which sees you searching for the culprit, is actually quite tough. Below, I'll run through the whole quest, plus I've included details as to the outcome and rewards for getting Gremla's tapestry back, or keeping the thief's secret.
