- Sabotage four alarm bells
- Three cover kills
Head to the le Cimetiere des Innocents to begin this mission and climb down and follow the wall south to find an entrance in the corner. There are two Opportunity Events in this missions, both of which are rather easy to complete.
Enter the search area and head straight for the alarm bell by the pile of skulls and sabotage it. Instead of continuing inside, return to the entrance and turn right to take the stairs down into the tunnels.
As you progress you’ll come across a group of guards harassing some rebels, but if you toss down a Smoke Bomb then you should have no problem taking them out. Continue through the tunnels until you reach a set of stairs and carefully walk up.
There are two guards here, both of which you can take out with Phantom Blade attacks, and then enter the courtyard and sabotage the second bell. Turn right and walk toward the gate and headshot the guard straight ahead and wait for the nearby Brute to check his body in order to headshot him too.
A sniper in the straight ahead on the roofs will spot you if you try and move around in the area, so run straight forward, past the plans, and climb up to ledge assassinate him. This leaves the nearby bell open to sabotage.
The area on the opposite side of the wall has two guards, one that is stationary and one that patrols back and forth. Wait for the patrol to begin walking away and then climb the wall and air assassinate the guard, followed by his buddy. You can now walk forward and sabotage the final bell, but watch out for the guard that patrols between this bell and the first one you sabotaged.
With all the bells now sabotaged you can return and pick up the plans to continue, but you’ll need to find a good hiding spot until nightfall. Head back to where you first entered the area by the first alarm bell and hop in the haycart until nightfall.
As soon as you have control hop out of the cart and take cover on the side of the cart to cover kill the guard leaning against it. There are two guards by the first bell, one standing by a tombstone and another patrolling the area between the piles of skulls. Wait for the patrol to turn his back and take cover on the tombstone for a cover kill and then turn around and run straight back into the outer area before the patrol turns back around.
Follow the covered walkway until you see another entrance with some guards and you should see a group of NPC gathered by a mausoleum. Hop over the wall and walk over to them and use Eagle Vision to spot a guard off to the left and right that face the mausoleum. Using line of sight and the last known position, drawn the guards over and cover kill them to complete the second optional objective.
There is nothing left to do now except kill Lafreniere, so walk to the left, toward the pile of bones, and you should see a hiding spot on the right that Arno can slip into. Lafreniere will walk right by this outhouse, so just wait until he walks by and silently kill him and then leave the area to complete this mission.