Find Elise and kill the thugs before making your way out of the maze and escaping.
Assassin's Creed Unity guide - Sequence 6 Memory 2: Templar Ambush - Escape the Maze
Getting the optional challenges in this mission can be a bit of a pain. Make sure you buy the Double Assassination skill from the Stealth section of the Skills character customisation menu.
- Four headshots
- Two double assassinations
This missions kicks off as soon as you exit the zone of the last one, so just follow your marker until you're close enough for an objective update.
Kill the Thugs
As soon as the objective kicks off, find enemies and headshot them. It's not easy if you're in open conflict, so you want to do this as soon as possible. Pistols, rifles, phantom blades and even berserk blades count. Whether you manage the feat or not, killing everyone triggers a cut scene.
Follow Elise into a maze and take out the three enemies here. Elise is pretty durable and deadly, so if you didn't manage all those headshots, take your time and have another go. As long as you get it done before you exit the maze, you'll be laughing.
Escape the Maze
You can climb the tower and spot a path out of the maze or even just wander through until you reach the exit, trusting to luck; it's not super long. But if you want the double assassination challenge, you'll have to seek out enemies standing in pairs. Use stealth to sneak up on them - don't be tempted by the gaps in the hedges you can slide under - and rack up the kills.
Since I have no idea where your final set of double kills will leave you, I can't guide you out of the maze, but here's a trick that works in every maze ever - imagine you have placed the palm of your hand on the left hand wall, and then just never lose contact with it as you walk around, tracing your way back through dead ends. You'll get out eventually.
Kill the Searchers
Now you'll work with Elise to take down pairs of enemies, which is good training for co-op missions. Start with the two by the narrow exit, then keep up with Elise by running through the streets, only slowing to walk and blend when you approach the targets marked for you. She'll eventually shout something about snipers; hit the rooftops and use air assassinations from above for best results. Eventually you'll get a cutscene for your efforts.
Escape the Thugs
All you have to do to end the mission is get away and become anonymous.