Quest Stages - TG03 (Dampened Spirits)

StageObjective
10 Speak to Maven Black-Briar
I've been sent to speak to Maven Black-Briar, head of the wealthiest most influential family in Riften. According to Brynjolf, she has a job of utmost importance for me and I need to follow her directions to the letter.
20 Speak to Mallus Maccius
Maven Black-Briar has sent me to Whiterun where I am to meet with someone named Mallus Maccius. Together, our goal is to bring down one of Maven's competitors, Honningbrew Meadery and discover where he obtained the financing to take her on.
30 Speak to Sabjorn
I've become a key component in a cunning plan to frame Honningbrew Meadery's owner, Sabjorn, and have him imprisoned. The first part of the scheme is to approach Sabjorn under the guise of assistance with a pest problem he's having thanks to Mallus's tinkering.
40 Sabjorn has provided me with poison I'm to apply to the nests deep within the tunnels under Honningbrew Meadery. As Mallus predicted, I should be able to use the very same poison to taint Sabjorn's mead as well.
45 Poison the Nest
50 Poison the Honningbrew Vat
60 Return to Sabjorn
70 Attend the tasting ceremony
80 Speak to Mallus Maccius
The plan worked perfectly and Whiterun's Captain of the Guard was stricken with illness when he drank the poisoned mead. Sabjorn's been carted off to jail and Honningbrew Meadery is now closed.
90 Identify Sabjorn's silent partner
Now that Mallus's position as the owner of Honningbrew Meadery has been secured, I need to find any information explaining how Sabjorn was able to fund this costly operation.
100 Return to Maven Black-Briar
110 Return to Brynjolf
200 The information I obtained from Honningbrew Meadery points to the same anonymous buyer of Goldenglow Estate. If successful, this individual would have completely estranged Maven Black-Briar from the Guild and destroyed it economically. It's becoming painfully obvious that it's time to shed some light on our mysterious adversary before they have a chance to strike again.