Part II - Dunwall Streets
After the loading screen, exit the room into a narrow corridor, where it is nigh impossible to miss the first collectible painting of the game - a portrait of the Pendletons entitled 'Custis, Morgan, and the Postulate Child' (Painting 1/2).
Grab it, and the 200 coins it represents (that's a lot of bath salts).
Follow the corridor out to the balcony, where Corvo vows to
raise up a furious counter-revolution escape the city and go into hiding. Safely descend the rooftops by using the steam pipes, or by jumping from peak to peak. If the latter, don't be afraid to leave stealth mode for a little extra sprinting distance. You won't need to be sneaky again until you reach rooftop with the leaky blue goo canister, just above ground level. Here the game sets you up for an easy drop-takedown (and of course for this playthrough, you'll want to opt for the non-lethal variation.)
Grab the dark bread from the table if you took any falling damage earlier, then follow the objective marker to see the guards discussing the ramifications of their treachery, and their plans to hunt you down like a dog. Once they split up, drop down to the guard post here, and enter through the top hatch.
The near guard will keep his back turned to you consistently, but the other two are in constant motion, so be careful- use the peek keys to check for watchers before moving. Break left, hopping over a railing into a lower courtyard. Open the grand door to your left, enter, then close the doors behind you. There's only one room accessible here, with a single guard strolling idly about. Take him out, then take the painting near the door (Painting 2/2) which is the last collectible of this chapter.
Behind the painting you'll notice the code '451.' Familiar numbers in videogame land, and you'll find you can use them to unlock the nearby safe. They also unlock the Special Action Dr. Galvani's Safe (3/4) Scoop up some silver ingots and gaze at the pistol ammo you probably don't need, then remember to re-stealth before heading back into the street.
Bear left again. You can exit to the next section here if you like, but if you're a dedicated scrounger, there are a few items worth coin in the house across the way, guarded by a single wandering enemy. You can also use the rocks here to mantle your way up to the Armory while the stairway guard is facing the wrong way.
There is, however, little quality loot beyond some copper wire and grenade you probably won't use (not a lot of low-chaos grenades in the world). You can methodically sleep-attack the guards, but they've only got about 10 coins between them. When you're ready, head down the street and into the next section.
Here, the treacherous guards will be instructing the citizens to stay inside. The body of a dead loyalist dripping his heartsblood down the wall indicates a dandy entry point- jump the wall, then head up the porch stairs. Look left to see a passage underneath the porch next door. Hide there until the speech is over, and hear yourself falsely accused of treason for the second game in a row.
When the guard above the crates walks away, climb the crates and duck through the alley to your right - the citizens here will see you, but they won't tattle if you don't do anything violent. For that reason, ignore the guard at the far end of the alley for now, and take the stairs up to your left. There's a single guard on the upper level here, and two below. A handy tip- the drop-takedown is technically silent- as long as the second guard isn't actually looking as you human-lawn-dart his partner, he won't be alerted. Take out the guards, and loot the place. It is, admittedly, pretty picked over, but there's a glass case with an umberwood hound statue worth a cool 50c.
Exit the building and go down the alley. That guard from before is likely loitering at the far end. Put him to sleep, then jump the railing that drops down the right side of the street.
As before you'll use a passage beneath a porch to sneak along the street here, and into an alley.
Keep right, passing what seems like an unnecessary number of dead bodies, until you reach a fire.
Use the boxes on your left here to mantle your way up to the rooftops. Jump over the sparking rail line, and take the pipe out to to sea.
You can now take the Dreadful Wale to the next chapter, but there are few lootables and achievements left here if you're looking for completionist cred. If so, swim left to the far corner of the docks, and mantle your way up past some oblivious Hatters to a blue blocked door. Turn around and creep to the edge of the balcony here.
Drop-stop one of the garish thugs and choke out the other, then loot the warehouse here. Some odds and ends, but the big-ticket item is the Southern Star Chart on the desk with some loose change.
Exit the warehouse, then bear left when you can, hopping over some rock to where you can see a couple guards staring at the Wale. Hang by the corner here- another guard will patrol right past you eventually, and you can choke him out and carry him away without the Wale-watchers noticing.
There's one guard patrolling the little interbay area, but no one else has eyes on him. Wait for your chance then choke him out.
Lurk by the stairs up to the street until you hear the guard shout to no one in particular about how much he needs to pee. Punish his coarseness with a trip to coma-ville, and stop off in hidden-body-opolis.
Ignore the guard in the guard post- he seems a tempting target, but too many other guards can see him. Instead just keep to the right side of the street- stay low and you can avoid detection. Duck into the pub here to pick a few pockets if you like- small rewards, but there's no penalty in Chaos or tactical advantage for doing so.
If you want, you can also unlock that door above the Hatters, for easy access to the docks later. Exit back into the street, keeping an eye out for the roving patroller. When his back is turned, duck through the gate to the previous section. The guard to your left is trouble, but the hedges to your right provide total concealment.
Move to them quickly, then up the steps and through the doors of the Dunwall Courier (pay no mind to the citizen on the steps, she doesn't even notice you). Ignore the guard for the moment, and quickly loot the lower rooms here, including an Umberwood Whale Statue. Then follow the guard up some opulent red stars and choke him out.
In the next room, you can hear a journalist being threatened by one of the insurrectionists. Do not choke out the traitorous dog until he actively threatens the newspaperman. Acting at the proper moment will win the printer's gratitude, and unlock the special action Freedom of the Press.
And that's the meat of Dunwall. There is loose change to be scavenged here and there, and guards to comatize if you want the practice. Once you've had your fill, swim out to the Dreadful Wale and talk to the clearly hard-done-by captain to set sail for the next chapter.