Assassin's Creed/Memory Block Seven

Back into the Animus you'll enter Masyaf where a crazy man will speak nonsense to you. Head up the hill to Al Mualim. About halfway up the hill you'll encounter a large group of fellow assassins. When you try to proceed past them however, they'll attack and you'll have to defeat them all to move out of the memory block. Use the same tactics as when you fought the large groups in the last memory block. Don't worry too much about your health though, as it will be replenished after you defeat the first wave. Once you do so, another even bigger group will attack. After taking a few of them out, Malik and his crew will show up to take out the rest for you. He's also come to the conclusion that Al Mualim has betrayed the Brotherhood from his investigations in Jerusalem, and you send Malik around the back of the fortress to occupy any remaining guards while you make your way to the assassin leader. Go through the citadel and find Al Mualim out in the rear courtyard.
 * Objective: Seek out Al Mualim

Al Mualim uses the Piece of Eden to enhance his own lethality and create supernatural opponents for you. There are four phases to the fight with him. First he starts by summoning the ghosts of all the targets you've slain. You'll take on all of them at once, and while they do a lot of damage if their strikes land, they are all one-hit counter kills. Next, he will split himself into a bunch of mirror images to all fight you at once. The real Al Mualim stands back, so it's likely you'll encounter him toward the end if you just try to go through and kill them all. Instead, use your Eagle Vision to discern the actual Al Mualim (the yellow one), and go for him. When you take him out, the others disappear.
 * Objective: Assassinate Al Mualim

Next you'll fight him honestly, but after you've done enough damage or you've performed a counter kill or even a grab break, he'll disappear and you'll be robbed of your entire synchronization bar. A single hit from Al Mualim at this point will start you back at the beginning of this third phase. When he disappears you'll have to find him elsewhere in the gardens. Each time you engage him, you'll need to inflict damage on him without taking any yourself. The easiest way to do it is with a counter kill or grab break. He does a guard break before he attacks, so if you're using the counter kill, be very quick or he'll swat your sword away and you won't be able to counter him. After defeating him three times with no synchronization, you'll break his spell and get your life bar back. The last phase of the fight is a normal battle where you must beat him like any other opponent.

After the death cutscene with Al Mualim, walk over to the Piece of Eden to trigger another event before waking back up at Abstergo.

Epilogue
After you hear from Vidic's boss, you'll find that you're experiencing a curious phenomenon called the "Bleeding Effect" where some of Altaïr's powers can now be accessed by Desmond – specifically the use of Eagle Vision. Use it on the empty floor space in front of you when you get off the Animus to reveal some hidden writing. Doing so again on your bedroom wall will reveal a ton of writing and will trigger the game's credits. After the credits roll, you'll be left alone in Abstergo's apartment. You can go into the Animus whenever you like and replay memory blocks or look for ../Flags/ or ../Templars/. Whether you're going to continue playing or not, be sure to at least enter the Animus and load a memory block so the game saves, or you'll have to rewatch the entire, unskippable credits again before using the Animus the next time you load your game. The story of Desmond and the Templars' attempted conquest of the world through the Pieces of Eden is continued in Assassin's Creed II.