In this guide We'll cover the Return to the Tower/End the Lord Regent's Reign mission in Dishonored. This is a very important mission. Some spoilers follow, as always.
First off, don't forget the 3 Runes in the Hound Pit's Pub area before stocking up and talking to Samuel. They are: In your room, You get one from Pendleton, and you get one for finding Emily - who has run off and hid from Collista.
Next, embark on your quest for vengeance and take down the Lord Regent - who has himself hidden away in his spiffy new Safe Room at the top of Dunwall Tower. Also, make sure you grabbed the skeleton key from Lady Boyle's Last Party, as it opens up some handy doors to and in the tower.
Here's a breakdown:
Watch beginning for 3 Runes in Hound Pit's Pub area
05:05 Bone Charm 1/2
10:11 Rune 1/4
12:31 Entering the Tower - second floor vent
13:55 Accessing the Broadcast Control Station
17:00 Bone Charm 2/2
20:06 Chick's body totally disappears
20:47 Going to the Torturer's Chamber
22:08 Rune 2/4
23:50 Lord Regent, his Safe - combo is 935, and Rune 3/4
25:40 Using the Audiograph for Non Lethal methods
27:29 Sokolov Painting 1/1
28:10 The Roof
29:24 Regent's Safe Room
31:01 Rune 4/4
32:23 Jumping off Dunwall Tower like a Badass
That covers it. As always, thanks for watching!