Run straight through the graveyard and the tunnel beyond. Once inside, jump through the V-shaped gap and turn left to find an opening in the brick wall; on the other side, slide down the slope. When you reach the position illustrated above, free run to the opening on the far side.
As you enter the main chamber, look for crates and barrels to your left. Use these to reach a suspended platform and, from there, a rope spanning the chasm. At the far side of the rope, leap to the narrow wooden platform and move around the corner. Jump to the solid ground below and head through the hole in the wall.
Follow the linear pathway until you reach the slope shown above, then move into cover to the left to avoid the bouncing boulder. Run to the top of the slope and continue until you espy a wall section marked by metal rings. Climb to the top of this.
Dozens of small boulders cascade down this larger slope, but there’s really no time to pick your way through: the server sweep necessitates haste. The exit is found on the right-hand side of the slope, though you can angle your approach slightly to take advantage of a natural barrier that will briefly protect Arno. Through the doorway, sprint for sunlight to escape the server sweep.
Climb up to the broken bridge, then free run towards the gap; though it seems quite a stretch, Arno will swing on a beam and make the crossing with ease. On the far bank, run up the slope.
On the battlefield, horns foreshadow the imminent arrival of projectiles fired from the Bastille. You can avoid these by taking cover behind fences, wooden barricades and natural barriers as you make your way to the portal in the distance.