At the end of Bleeding The Leech, you’ll need to decide whether to burn or keep Sister Frideswid’s book. The outcome of this choice is fairly insignificant. The only thing you will gain from keeping the book is that it will be visible in your sleeping quarters at the longhouse in Ravensthorpe.
Burn Sister Frideswid’s Book
Erke agrees with your decision and states that whatever good is contained within the book isn’t worth the bad. The book is thrown in a nearby fire and the quest ends.
Keep Sister Frideswid’s Book
Eivor states that the book contains many cures, and is therefore worth keeping. Erke agrees that the sacrifice of the dead can mean something if the book is used for good.