So Rais has finally been heard from... He really does have more than a small reason for being angry with you, though to be honest since his entire life appears to be motivated by revenge that is not saying much...
When you reach the Safe Zone and marker you talk to Fariq and he fills you in on his needs - you do a deal with him - he tells you how to get in, and you will help him with the kid.
After you talk with him that will generate some new Side-Quest Flags for you to hit.
Side-Quest: Chasing Past
There is another marker at the Old Town Tower but that turns out to just be Michael and a chance to talk to him and learn that he survived the blast project.
Gaining entrance to the Museum means swimming in underwater - and once inside remember to collect the reward for the Side-Quest Chasing Past.
Using the door you go into this Instance Zone - reminding yourself that you are there to rescue Jade - well that and kill as many of Rais' men as you can!
Man that was a long swim - was not sure if I would make it to the first air pocket! Then I almost didn't make it to the second one...
Climbing up and in gets you a seizure - but hey, you are there! Break the barrier and head inside and you can then call Troy on the radio. Getting in is like a maze but, once you are in, you have no trouble spotting Rais' men - and they spot you!
As you enter the main area you are confronted by Rais - and he shows you Jade sort of... The goal changes to Eliminate Rais' Guards - well we were going to do that anyway so why not?
Mind you they throw bombs at you so you have to be aware of that at all times - but they also die really well to shotgun blasts - just saying.
After some witty trash-talk with Rais he sends in some more guards - but that group is on the walkways above you.
After you take out the last of the guards above Rais' taunts you again with Jade and invites you to come rescue her. Make your way up using the stone things and then follow the marker to find a few more guards defending the route. Nothing you cannot handle though.
Once you get inside there are more guards using the corners as cover - but as you get past them the seizure happens again - they seem to be coming quicker now.
After getting outside you survive yet another ambush and then you find the path blocked by an entire army of the undead! Time to start burning them up right? Hope you brought lots of Molotov's!
After you get the XP from killing a bunch you can then use the upper walkway to get across - though bear in mind there is a sniper. At the end of this hall there are more infected to deal with then you just drop down and head through the door there, and you will survive yet another seizure.
You finally reach Jade and she is woozy but she seems okay... Rais then starts talking trash again - then he releases another army of infected against you. Call this Arena 2.0 right? Fortunately this time around you are better equipped.
After you help Jade kill all of the infected you need to escape the Museum - but Jade seems to be doing very badly - Rais tells you that she was bitten - and infected - hours ago!
Rais drops an Antizen to you but tells you that you have to make a choice - Jade or you - you are noth about to turn. Jade asks you to take the Antizen and then promise to kill her when she turns. She then runs away and you start hearing her on your radio...
The infection is getting worse - as you wander around half-stunned looking for the way out. Now you start to hallucinate - clearly you should listen to Jade and use the Antizen on yourself. You continue to make your way through the messed up reality as Jade talks you into taking the Antizen yourself.
You follow the Jades through the nightmare world and then eventually you confront her and she injects you with the Antizen herself.
Rais mocks you yet again - then sends the remaining men to kill you both. Jade takes out the bad guys but then turns and you have no choice but to end her. Yeah, it sucks, but it is what it is.
Rais still wants you dead though - and he sends his last man down to do it. You have to battle Tahir melee - the whole time he is taunting you and then more guards attack.
This battle is a variation on the Arena - all your kit has been taken and so you need to try not to get hurt as you deal with the enemy.
When you complete the battle you unlock the Achievement: Tied Loose End (25g) Deal with Tahir.
Your goal now changes to Leave the Museum. On the way you radio Troy and report what happened.
She fills you in on the details for what you need to do next - which is meet her. So head to the marker and kill the guards, then get your stuff back. Unfortunately now you need to sort through all your crap again to restore what you need - so do not forget your crafting kit right?
When you are ready zone out and that will cause you to contact the Doc. Your next task is to meet with Troy - she tells you that you need to install the Amplifier at the highest point that you can - and then set it up so it can broadcast.
And with that we complete the mission!