Walkthrough - Deus Ex Human Revolution Director's Cut - Montreal

This is a minimal walkthrough for Deus Ex: Human Revolution (Director's Cut), Montreal -- the investigation of the PICUS building and meeting Eliza Cassan. We only go over things you may not have considered; a detailed walkthrough is already available from the Deus Ex Wiki.

M1 - Confronting Eliza Cassan

• Keeping your Ghost bonus while doing Takedowns on all enemies becomes harder now, but still not impossible.
• It would be very good to have a Silenced Armour Piercing pistol but not absolutely necessary. They are useful for taking out disabled robots quietly.
• Keeping a Stun Gun on you with some ammo also starts being a very good idea, for handling cameras.
• Even so, there are generally options to bypass security in a safe and less-stressful way and get to the Security computer to disable cameras and robots first. When doing so, be mindful of going through doors that may be locked from the other direction; doing so automatically unlocks the door, and you miss the XP you would have gotten from hacking.
• Before riding down the finucular, have a Stun Gun and at least 2 rounds of ammo.
• At the bottom of the Finicular is a storage area and two guards will walk to the center and stay there a while. There is generally no time to handle the camera without setting off some kind of alarm.
• You can Double Takedown the guards before they disperse on a patrol routine, but in order to do so safely you need to wait till the camera is facing away, and afterwards Stun Gun the camera before it turns and sees the bodies. You will probably need to stun the camera again to give you time to hide both bodies.
• Yelena Fedorova 
• They give you lots of ammo (in lockers around the perimeter) to shoot her with, so run-and-gun is theoretically viable as you can heal while she is cloaked and waiting for her special bomb attack to recharge. Or, you can use turrets, just like on Barret.
• Before entering this mission, have some way to break down walls (augmentation or guns), and lots of hacking help since you are under a lot of time pressure to hack at least two items. Also helps to have the Icarus augmentation for long falls.
• Eliza will give ongoing commentary and hints as to when Yelena is coming for you or when she is waiting to recharge while cloaked. You can use that as hints for how much time you have to hack.
• Hack the door. This opens two doors with ramps up. At the top of one ramp is a weak wall. Bust that if you have time as it's a quick escape from Yelena if you need it.
• Once upstairs, there is a terminal protected by lasers. Do not simply use your Cloak to get past the lasers as Yelena will come for you anyway and her attacks will probably trigger the lasers. If you haven't reprogrammed the ceiling bots, they will kill you.
• Go to the panel on the side of the room. It can take a long time to hack so instead bust the wall and turn off the power to the lasers.
• If Yelena is coming, run. Or if you can do it fast enough (you may have close to 90 Nukes and Stop Worms by now), hack the computer and reprogram the turrets. If you really have trouble with time, use Automatic Unlocking Devices, which do not require you to stand around--Use the device, run, and come back later to use the computer.
• If Yelena is chasing you and you need time, run toward one of the poison gas pillars and either turn the valve or shoot the glass (or let her shoot the glass). Yelena likes to come close so she will end up in the gas. This will either buy you time to escape (especially if you have the Rebreather augmentation) or hold her in the room while the turrets shoot her some more.
• Stay in the room and hide behind the pillars until Yelena is killed by the turrets.
• Collect all loot. Turn the power back on for the lasers and hack the terminal. Plant EMP mines on the turrets then turn them back to "Default", making them hostile and triggering the mines to destroy them for a total of 90 XP. Destroying one any other way makes the other one hostile to you and shoot you.