- Two Snipers driven berserk
- Two kills from hiding spots
Find La Touche
When the mission cut scene ends, you'll be in (near) position to complete your first challenge: drive two Snipers berserk. For this, make sure Mr. Arno Dorian has some Berserker Blades, and close the distance between you and your foes on the nearby rooftops. We'd suggest waiting until the one directly in front of you isn't looking, then sneaking on the roof just above him. Use your Eagle Vision to see when he turns his back, then nail him. There are two more on the rooftop with the small awning a few meters to the northeast.
Your next challenge isn't for a few more minutes, so for now, you'll want to make your way to the northeast side of the building. It's here where you'll find a window you can climb through, but you'll also want to take cover very quickly. There is a meeting between some unfriendly foes just a few feet away.
From your position of cover, you'll see your adversaries in the middle of the room, but you're headed out the door closest to the side of the room you are in, passing through another to find yourself on the balcony. From here, activate your Eagle Vision to spot La Touche and complete your objective.
Tail La Touche
This objective isn't as hard as it seems, given that La Touche likes to stop and chat as he's making his way through the building. You aren't going to follow him in the direct sense, instead jumping across the chandeliers and making your way to the opposite balcony.
Take cover next to the door, then activate your Eagle Vision to spot the two guards in the next room. When their backs are turned, enter the room and duck into the hiding place. When one of the guards walks by, press the attack button to perform a kill from a hiding spot. You might want to leave the second guard alone - his dead body could be spotted by La Touche as he makes his rounds.
Continue heading south through the building until you see a room with a stairwell, as well as a guard who is moving back and forth between two doors. Wait for the guard to turn his back to you, then sneak into the hiding place in the middle of the room. If La Touche still hasn't arrived, perform a kill from a hiding spot to complete your challenge. If La Touche is close, wait until he passes and then do it. Again, no need to draw attention to yourself.
When the guard is dead and La Touche is upstairs, feel free to safely exit your hiding spot and turn left, going out the open door and climbing up the wall to get a view of the proceedings through the open window. Just be sure not to get spotted, and of course, don't go in the window.
After the meeting, La Touche will head back to the ground floor. Leave him be, continuing to use your Eagle Vision to keep tabs on the guy. Shortly afterwards, your objective will update.
Find a Place to Spy on the Meeting
Make your way down two flights of stairs to the basement, then pick the lock on the door that serves no purpose other than to provide you with an alternate route. When you finally enter the room, a cut scene will play and your objective will be complete.
Escape the Area
When the cut scene ends, you'll want to activate your Eagle Vision to spot the three guards in the basement. If you picked the locked door, you can silently kill all three. If not, you have two other options. First, you can fight and destroy them with your sword, or secondly, you could hit one with a leftover Berserker Blade and start a fight. It's completely up to you.
Whatever methods you use to deal with those guards, we opted to leave this building by traveling all the way back to the window from which we entered. However, you can leave any way you want. Just know that you'll likely face some opposition, but there is no reason to worry about making noise at this point. Just kill whoever stands in your way and make your escape to complete the memory.