99% Players MISSED tis SECRET SCENE in Ratway

99% Players MISSED tis SECRET SCENE in Ratway

00:00 Beginning, the first scene with "Gissur" in quest "Diplomatic Immunity"
00:22 If Gissur is not dead, then he appears in The Ratway, and is looking for an agent of blades
00:33 Revealing us Gissur goes somewhere
01:04 Follow Gissur
01:13 Secret meeting Gissur
01:36 After the event

So for this scene to show, you have to (in order):
wait until Gissur and Rulindil finish chatting and until Gissur leaves the embassy
progressed somewhat into the thieves guild
ask Vekel for Esbern
follow Gissur outside the flagon to see him rat you out
wait for the thalmor to charge in and then follow them in
keep hidden while the thalmor and thieves guild have an argument