It's recommended that you choose Garnier de Naplouse (Grand Master of the Knights Hospitalier) as your second target because the Throwing Knives and Tackle ability you earn might come in handy when you face Talal. If you've assassinated Garnier before you probably remember being shoved around by mental patients. This guide will show you a cool way to assassinate him without anyone laying a hand on Altaïr.
INVESTIGATION
Two of the investigations actually yield useful maps of the Hospitalier Fortress interior. If you only do two investigations, make them the Informer at the western sea wall next to flag #28 and the Pickpocket in an alley near flag #12 on this map. To view the maps you acquire in-game press the pause button, select "Memory Log", use the Left and Right Triggers to cycle through the completed investigations, and do "View Attachment".
One map shows where the crazies walk (i.e. everywhere). The other shows the locations of candelabras and of Garnier's six favorite patients. The latter has minor errors in the locations of patients 3 and 5. Those errors are corrected in the maps below, in which I've consolidated the information into "first floor" and "second floor" views.
PREPARATION
Before going to the Assassin's Bureau, make sure you explore the Hospitalier Fortress while it's lightly guarded. Look for the big building pictured below on the north edge of Acre's Poor District. Flag #7 is on the roof over the front entrance. Proceed into the rear of the building. It's kind of dark in there. You may want to adjust the brightness of your display (Pause | Options | General | Brightness) to make sure you can see what's going on.
The main thing to practice is navigating through the ceiling beams and candelabras. This is not nearly as easy as Free-stepping through a Souk. When two ceiling beams are connected by a diagonal brace, make your way along that. It's faster to walk the beams in high profile (while holding the Right Trigger). You won't ever fall from a beam unless you also press the A button (X on PlayStation 3) and try to jump. It should only be necessary to jump to or from a candelabra or wooden catwalk. See if you can make it from the ladder in the southeast corner to the broken window at the southwest and back again without touching the floor. Now imagine doing it with guards chasing after you.
Another thing to practice is getting from the ground up into the ceiling without using a ladder. Having trouble? One trick that works for me is to jump straight up. Let go of the Left thumbstick, hold Right Trigger (R1 on PS3) and tap the A button (X on PS3). Usually Altaïr just looks like an ass when you do this, but if there's a beam right over his head he will grab it, allowing you to pull yourself up. There are several places where this is possible. Climb onto a paneled wall or a hospital bed with a canopy, position yourself below a ceiling beam or the edge of a catwalk, and jump straight up. There are other ways to get up, such as running up a wall and back-kicking over to a candelabra. Figure out what works best for you.
Locate patients 4, 5, and 6 on first floor map below (tip: their beds do not have canopies). Work out a short escape route from each up into the rafters and over to the broken window to the east.
APPROACH
Once you get the feather at the Assassin's Bureau and return to the Hospitalier Fortress, you'll find the front entrance now guarded by a four man post. Just as when entering a city, there are four options for getting past them:
Ah, yes, the widely unused dead body distraction is the preferred way to enter the Fortress. There are two stationary guards facing each other at the top of the stairs leading to the front entrance. Select your Hidden Blade and do a low profile assassination (to the front or back) of either guard. As the four guards leave their post to investigate, walk right through the front door into the open courtyard.
If you choose the roof approach, remember that there are eight guards up there and two hiding spots (a roof garden and a haystack) if you need one. It's possible to climb down into the courtyard. You don't have to suffer a huge fall and lose synchronization.
Saving the citizen at the bottom of the stairs gives you two sets of Scholars for the price of one. The first quartet gets you through the front door and the second waits inside to the west (regardless of whether you actually used the other Scholars to enter). This second set is useful primarily for protecting you from mental patients. However, we won't be needing them.
HUNT
After the gruesome leg breaking scene, pass through the door to the east (ignoring the guard there, if any). The stylish assassin can't be bothered with crazies, so climb the ladder in the southeast corner and take to the rafters.
The doctor tours around the Fortress talking to his six patients. You heard it here first: Garnier selects which patient to visit next at random. That includes which patient he visits first. So if anyone tells you that the fast way to assassinate Garnier is to rush over to patient 6 because he goes there first, that person either got lucky or is misinformed.
The good news is you can hear Garnier from anywhere in the Fortress. If you can make out what he's saying over the ramblings of all the crazies, then you can tell exactly where he is. Use the following dialogue guide. The patients in the east wing seem to be more satisfied with their health care than those whiners in the west. Only patient 2 (Mr. Broken Legs) actually moves while he talks.
Patient 1:
And how are you feeling?
What have you done to me?
Ah, yes, the pain. It hurts at first. I won't lie. A small price to pay. In time you'll agree.
You are a monster.
I've been called worse.
Patient 2:
My legs. You bastard! You broke both my legs.
For your own good. You were going to run. To where?
Get away from me.
One day we'll look back on this and laugh.
I'll kill you.
I doubt that.
Patient 3:
I trust today is better.
What do you want?
Only to help you.
No, you want to hurt me. It's all you've done since you brought me here.
My child, the very fact that we're having this conversation shows that we've made progress, or do you forget the way you once were?
Can't remember... before... all a blur.
Ah, it will come back in time. Then you'll see.
Patient 4:
He stirs.
How, how did you do it?
I have my ways. The worst is over then.
So tired.
Then rest, my child.
Patient 5:
They say you can walk now. Impressive!
Been so long... almost forgot how.
Wonderful.
I don't understand. Why did you help me?
Because no one else would.
Patient 6:
Ah, he's awake.
It's you!
And how does it feel to be home again?
I don't know how you did it.
It wasn't easy I assure you. You fought hard at first. Most do, but now it's done. The hard part's past.
I owe you my life. I'm yours to command. Thank you. Thank you for freeing me.
Thank you for letting me.
None of the guards will notice you moving about the ceiling. Apparently the only person capable of looking upward is Garnier himself. Pay attention to your witness indicator. If you have a red flashing circle and a chirping noise that means there's a clear line of sight between Garnier and Altaïr. To know for sure if he can see you, look at Garnier. If he's far away or his back is towards Altaïr, it's okay to jump. Otherwise, you don't even want to be caught on a ceiling beam! If he's coming your way, quickly move out of his line of sight or onto a candelabra or catwalk where he will never notice you.
ASSASSINATION
You can air to assassinate Garnier from any ceiling beam but not from a candelabra or catwalk. (UPDATE: I was wrong. You can do a running air to assassinate from candelabras and catwalks. That means you can wait undetected on a candelabra and assassinate Garnier when he comes near.) The trick is to strike at a point that will facilitate a quick escape through the broken eastern window. Wait until he comes into the eastern wing to visit patient 4, 5 or 6. You can strike while he's stationary (talking to a patient) or while he's walking the halls. Wait on a candelabra or catwalk until he passes by and then move into position behind him on a nearby beam.
When you're ready to strike, make sure your Hidden Blade is selected and target Garnier. Pull and hold the Right Trigger (R1 on PS3). At this point the Control Heads Up Display should change to show the option "assassinate" for your armed hand (if it doesn't, maybe you're too far away or are standing on a candelabra). Press the X Button (Square on PS3) to swoop in for the kill.
ESCAPE
The preferred escape route is back up into the rafters and out the eastern window. It's easy to get flustered and try to run up a stone wall or to fall out of the ceiling. Just keep your cool and remember your training. Leap through the window onto a rectangular building. There are five nearby hiding spots: two roof gardens and three benches down below. Find one and become Anonymous. From this location you can make it all the way back to the Assassin's Bureau on rooftops.
If you flub up the primary escape route, your backup plan is to run out the front door. Follow the main hallway back to the open courtyard. A wishing well marks the location of the door (that's good to know when your in a full sprint). From the front door, continue straight ahead (south) down a series of staircases. At the bottom of the last staircase there will be an obelisk and some vigilantes (or a citizen being harassed by guards if you haven't already saved her). Turn slightly to the left (southeast) and look for a one story building at the top of some stairs that lead down to the east. Scramble up the side of that building and continue sprinting to the south. Free-step across some beams and land in a haystack. It's hard to explain so I've also included this escape in the video above.