Finishing Dorn's quest

Ridcully

I've killed Simmeon but the quest isn't showing as finished. What else do i have to do?

Valci

I don't think you need to do anything else ... I think it's just that there might be some interactions left... Not 100% on it but that would be my guess...

ThacoBell

What version are you playing on? Pre 2.5's journal is glitched and sometimes doesn't close completed quests.

Another possibility: I haven't done Dorn's quest in some time, but I believe he has one more talk about his purpose after killing Simmeon.

Ridcully

V2.3.67.3 Just had a Journal quest entry entitled "Bad to the Bone" but its still un finished

ThacoBell

It could be the journal bug. This is supposedly fixed in 2.5. Quests can fail to be completed in the journal at random.