Quest Stages - TG07 (The Pursuit)

10 Meet Karliah at the Ragged Flagon
I'm on my way back to the Ragged Flagon to meet up with Karliah. Using the information obtained from Gallus's journal as proof, I hope to convince Brynjolf of Karliah's innocence and Mercer Frey's betrayal.
20 Follow Karliah
30 Speak to Brynjolf
Brynjolf has been convinced of Karliah's innocence and Mercer's betrayal after investigating the Guild's treasure vault and finding it empty. Of greater mystery is the fact that the vault can only be opened with two keys and is utterly impervious to lockpicking. How Mercer Frey could have breached it is a mystery to us all.
40 Infiltrate Mercer's House
The hunt is on and I'm on my way to Riftweald Manor, Mercer Frey's estate in Riften, to locate a clue as to his current whereabouts.
41 (Optional) Shoot the mechanism to lower the ramp
42 (Optional) Speak to Vex about Vald
50 Discover evidence of Mercer's location
60 Speak to Brynjolf
I've discovered some plans in Riftweald Manor. This must be where Mercer Frey is headed. I should bring these the Brynjolf as soon as possible.
200 Brynjolf is convinced Mercer Frey intends to perform one final heist before departing Skyrim for good. According to the plans I discovered in Riftweald Manor, he's after the "Eyes of the Falmer," two gems of enormous value. If we have any hopes of intercepting Mercer, we need to proceed to their location immediately.