The Hidden Blade Assassin's Creed in Depth

Sequence 2: A Simple Plan from Assassin's Creed Syndicate
David Brewster Assassinated and Area Escaped with no other kills. Four Knockouts are unavoidable.
* * *
RULES:
1) No Kills or Knockouts except Targets, unless Required.
2) No Detects except upon Assassination Moment
- Awareness Meters are allowed.
- I will try to avoid being detected during Assassinations as well, but if it's necessary, it's fine.
3) EQUIPMENT:
- Wear the Upgraded Beer Collector Belt for Jacob and the Upgraded Aegis Cloak for Evie.
4) No Side Objectives
5) No HUD except Awareness Meters and Tool Indicator

This video's pretty long because the mission has a large number of checkpoints for the player to go through, rather than one seamless stealth playground. The mission can be solved almost completely through Routing alone. The only time any real patience is needed, is when I'm Stealing the key from the guard talking about rats. I just have to wait for his conversation with the other guard to finish and for him to put his back to me.

At the start, I have to Knock Out one guard (the Whistle tutorial) because the game won't let me advance unless I do.
Later, when two guards are interrogating an informant, those have to be neutralized as well. I tried talking to the informant before they were dealt with, inside the Smoke field, and the game doesn't give the option. Instead, the cutscene automatically triggers once both guards are neutralized. The fourth and final mandatory KO is when I'm moving through the side-rooms into the Laboratory. The two guards standing in the tight passageway will both react if I walk into one of them with my body hard enough to move them out of the way. In this video, the guard on the left walks backwards out of the way, but this is not reliable and he will not always do it with the same timing. It is possible, though, to just slip past them if he does.

Finally, during the Assassination itself, fans who played Unity will notice that it is no longer necessary to Kill Targets using the Hidden Blade only - you can now Kill them with any weapon that drains their HP to 0.