STORY 11 - The Museum
Note: This mission contains heavy amounts of gunfights and battles in enclosed rooms swarming with infected. Bring Medkits. Lots and lots of medkits. Camouflage can help, but only against the infected here, Rais's men are still going to hurt. Oh, and bring a rifle with max ammo to deal with Rais's men. They all use rifles, so your ammo reserves will top themselves up as you go.
Find the Museum custodian
Travel across the rooftops of Old Town to the marked rooftop garden. When you get there, the custodian will be waiting just inside the door. He'll try to convince you to deal with the child he has with him but you can do that sidequest later. After the dialogue ends, you'll know how to get inside the museum. Looks like we're heading out for a little swim folks.
Find the underwater entrance in Emerald Pond to get into the Museum
You'll need to head a fair distance to reach the brown/ green waters of Emerald Pond. Splash down into the water when you arrive to avoid the undead and swim out towards the marker at the base of the cliffs. As you near it, it will change into a large yellow search area.
Dive below the surface and examine the base of the cliffs to see stairs leading down to a tunnel. This is your ticket inside the Museum. Keep this entrance in mind if you intend to do sidequests later as this is the only accessible entrance to the place.
The map will update to show you the tunnel path in yellow as you swim inside. In the first large square room, you can surface to catch your breath. Stay on the surface of the water and look around to see a gap in the metal fence to the East you can climb over. Splish splosh back into the liquid below and through an underwater gap in the fence to the South. Surface and look to the East to see a set of stairs leading up out of the water for you to take.
Find a way into the Museum
In the first room you reach, the locked door on the right is inaccessible for now until you complete a certain sidequest. So ignore it. Instead, open up the red door to enter the Museum.
On the other side of the door, you'll arrive inside a small square room with stairs leading down into more water. Gaaaaasp Splash! In the water, you'll need to move as fast as you can along the path as there are no air stops this time. Head North and look to the second rusty fence on the right to spot a hole to pass through. After swimming through the hole, turn South and look to the left for another passage to swim down.
At the last metal fence of the passage, you'll be able to see a hole in it to pass through. On the other side of it, swim North and then East when you near the wall to find stairs leading upward. At the top of the stairs, you'll finally be able to surface for air. Jump over the rubble here before plunging back into the water on the other side.
Down another waterlogged set of steps and continue straight ahead and through the hole in the fence. On the other side, turn South (right) and weave around the fence ahead and look to the West (right) to see another tunnel to swim through.
Head for the marker in the center of the dead end room and surface in the hole in the middle. You'll see a heap of ledges above you with daylight shining down. Start clambering and clattering your way up to the open air once more.
Or not... At the top you'll enter a dark passage with a fragile wooden blockade in your path. Kick it to break it apart. You'll be facing a series of parkour obstacles in the linear corridor. The idea is to stay as high up as you can due to the fact you cannot use the grappling hook here (gotta love when they do that).
Follow the linear path, clinging to ledges and kicking down rotting doors until you reach a hole in the wall overlooking the courtyard at the front of the Museum with two of Rais's men below you. Pull out your pistol or rifle and pop their heads before emerging into the sunlight, like some creature dredged from the murky depths of the ocean.
Ensure you are fully prepped with plenty of medkits (minimum around 20 to be safe) and plenty of ammo before entering. Make sure you have your gun out and loaded as you are about to walk into a major firefight with Rais's thugs. Open the metal gate when you are ready and a scene will take over.
Eliminate Rais's guards
After the scene, you'll be in cover behind a post with several thugs firing down at you. They will also lob DIY grenades at you as well that deal painful damage if the blast connects (watch for and move away from the grenade indicators when they appear).
The area you start in is actually a good spot to fight from as you can retreat around the corner nearby to avoid grenades and emerge from around the post to take potshots. This is the first area where the medkits are really going to come in useful.
Keep an eye out for the men on the upper level as they will often be hidden behind panes of glass until they open fire on you. Take your time here, there isn't really any need to rush. Avoid the grenades and work on picking off the thugs one by one.
You'll have to deal with at least six thugs in the first room before you can climb to the upper level with one hidden guard waiting at the entrance to the marked hallway. Once he is down, you'll see the triangles of two more guards waiting down the hallway for you to dispatch..
You'll emerge on the upper floor balcony (shaped like a figure 8), overlooking some displays below. When you descend to the lower level and pass through the glass doors towards the new marker, take cover behind the first information panel here as more enemies will emerge from cover ahead to fire upon you.
Continue lining up headshots and clearing the immediate area. Move up to the furthest poster and take cover. Two of Rais's men will open fire through a glass window ahead. Peek out and end them.
Once those two are down, carefully approach the windows they just shattered and fire through at the remaining enemies inside. After taking down any that you can see, quickly jump inside and take cover behind a pillar as more enemies open fire on the opposite balcony.
Once the room is clear of gun toting enemies, examine the open hole in the wall on the far balcony to find a large hallway teeming with undead. This section can be pretty tricky as it relies heavily on you movement and gun-play skills. Your movement is also hampered by the low ceiling and narrow ledges.
Climb up to the platform overhead (above you when you look through the hole in the wall). If you look to the left, you'll see a narrow ledge with a walkway behind it. If you jump to it, you can actually land on the ledge and walk along it to a hole in the railing and into the safety of the walkway. The ledge is very narrow though and gunmen may open fire as you move along it, so be as quick as you can and as accurate in your jump as possible or else fall into the undead crowd below.
If you attempt to move further along the ledge, past the entrance to the walkway, you will be shot. Instead, jump out onto the platform in the middle of the hall and quickly target the enemies at the far end of hall on the upper floor.
If your shots are accurate, you should be able to bring them both down without losing too much health. Once the hall is clear of humans, jump back to the walkway on the left and use the left ledge to reach the far end of the hall safely. As you reach another balcony overlooking a square filled with more infected, your objective will change.
Kill the infected
Now it's time to deal with the other enemy threat. The square room below needs to be cleared of the living impaired. Depending on your resources, you can simply fire for headshots (aiming at the canisters on the hazmat zombies as well) or lob explosives into their midst to thin out their numbers before descending and engaging the remaining undead.
If you intend to take them all on in melee, make sure to keep moving after you land to avoid being blindsided by unseen infected.
Rescue Jade (redux)
Once the square is clear, push open the large metal doors to walk into a scene.
Help Jade and kill all the infected
After the speech ends, the metal doors will open and a swarm of infected and multiple virals will flow into the room. Concentrate on taking down the virals ASAP as these ones seem will constantly chip away at your health by flanking you if you let them.
If you have the opportunity to use camouflage it is a real showstopper here. You can calmly walk around killing everything in the room (especially if you have the stealth kill ability). This is the other section where those medkits are gonna come in real handy.
Escape the Museum
When you manage to eventually clear the room, it's time to get the hell out. Open the marked door and another scene will take over. Rais really likes the sound of his own voice doesn't he? What follows is one of the most interesting sequences of the game (I won't spoil it for you). The path is linear though, so you shouldn't have any problems reaching the end.
After trip is over, Rais will decide enough is enough and throw his second in command at you. Smoke grenades will land in the middle of the room and fill the area with a hazy gas. Thankfully it doesn't obscure visibility much. Tahir will rush out of the smoke and begin slashing at you with his machete. Hope you've noticed your medkits and other weaponry is gone. You'll be equipped with a machete as well.
Tahir acts like a supercharged thug with a few extra abilites. He will charge you with his machete (counter this with kicks and swings of your own weapon, forcing him to block or take damage). He will also raise his hand and throw knives at you, which can be dodged by strafing left or right.
Use swing or two followed by a kick as hit and run attacks to chip away at his health pretty safely. This should allow you to avoid taking damage, which is the main concern here due to the lack of recovery items.
When he drops down to around a third of his health, three thugs will join in the fight. As soon as you see them, turn you attention to and bring down the thugs quickly or else you'll take constant chip damage from their thrown weapons and suffer blindside attacks.
Once the other thugs are gone, continue your smackdown of Tahir until he finally falls. When he does a scene will take control. After the battle you will also obtain Tahir's orange machete. It is quite possible to complete the whole sequence at 150 starting health without dying once (see the video).
Leave the Museum
After regaining control, follow the marker towards the exit of the Museum. When you get close to the main doors, you'll stumble across two more thugs guarding your belongings.
Take your stuff from the bag
Take them down fast and recover your items from the bag.
Leave the Museum (again)
Open the nearby metal door to finally leave the Museum.
Meet with Troy
Travel all the way back across town and climb up the massive structure to talk to Troy on the outlook at the top. If this was Assassin's Creed, we'd be using this as a synchronization spot. Talk to her to conclude the mission.