Quest Stages - TG04 (Scoundrel's Folly)

10 Speak to Mercer Frey
After the revelations at Honningbrew Meadery and Goldenglow Farm, it's time to put the pieces together and shed some light on the Thieves Guild's anonymous adversary.
20 (Optional) Speak to Brynjolf
Mercer Frey has pointed to Solitude as my next destination. I'm to meet up with an old Argonian contact for the Guild named Gulum-Ei. It's hoped he'll be able to identify the Thieves Guild's anonymous adversary.
30 Speak to Gulum-Ei
35 Steal case of Firebrand Wine
37 Get information from Gulum-Ei
40 Shadow Gulum-Ei
As predicted by Mercer Frey, Gulum-Ei proved to be quite stubborn and refused to reveal any useful information. I have no choice but to shadow him during his daily routine and discover if he's up to anything that could be used as influence to make him divulge the truth.
50 Confront Gulum-Ei
55 Find alternative source of information
60 Return to Mercer Frey
200 Thanks to Gulum-Ei's confession, a former member of the Thieves Guild named Karliah has been identified as its anonymous adversary. Worse still, I've discovered that she was the same Dunmer who murdered Gallus, the Guild's previous Guild Master and who's apparently resurfaced after all these years to do the same to Mercer Frey.