The Hidden Party

The Hidden Party was a virtual representation of one of Altaïr Ibn-La'Ahad's genetic memories, relived by Desmond Miles in 2012 through the Animus.

Description
With two keys in hand, Altaïr traveled to Jerusalem to find Lord Basilisk, holder of the third key.

Dialogue
Altaïr left the man's shop and made for the rooftops. As he approached the ground, a group of guards noticed him. Altaïr killed the guards and continued on his way, until he noticed a hill with several groups of civilians he could eavesdrop on. Altaïr made it to the top of the hill. Learning where to go next, Altaïr made his way to the gardens and approached Ayman. Altaïr interrogated Ayman, applying pressure to his back. With his newly-obtained knowledge, Altaïr continued on to Lacoeur's villa. Altaïr fought his way through the guards in the courtyard, eventually arriving at a drawbridge. Altaïr used his grappling hook to cross the gap and continued traversing the rafters until he fell into a weapons storeroom. Altaïr killed the guards inside and encountered a man nearby. The man opened the weapons storeroom door, allowing Altaïr to leave. Altaïr left the man and found the entrance to the secret passage. Altaïr killed the guards in the courtyard and moved four metal crates onto the four buttons, opening the secret entrance. Altaïr entered the passage and stepped on a switch, opening a distant door. Altaïr made it to the door just in time and entered the castle, encountering Basilisk. Basilisk attacked Altaïr, who engaged him in combat just long enough to grab the key from his neck. With his prize, Altaïr ran out the door.
 * Kadar: Well met, Altaïr!
 * Altaïr: Good to see you, Keeper!
 * Kadar: What is it that you need?
 * Altaïr: Lord Basilisk. I learned that he is in Jerusalem.
 * Kadar: Oh, an ambitious man, I see. He is a fearsome, feral warrior. Lord Basilisk idles in the King's wake. You'll spot him outright. But entering the palace of the King of Jerusalem is no small feat, I warn you. Although, as it happens, you came at the right time. The King will be holding a small party; nothing to be made public. But still, he will be out of his fortress and somewhere in the city. It should be easier for you to reach him. I don't know where this party will take place; you must find out.
 * Altaïr: Where could I learn this information?
 * Kadar: Try the City Gardens: it's the perfect place to pick up gossip on the nobility.
 * Altaïr: Thank you, Keeper.
 * Kadar: One more thing. We also have a man in the lower ranks of the King's staff. We haven't heard from him. Look into it, see if you can help him.
 * Altaïr: Alright.
 * Kadar: Good luck, Assassin!
 * Guard: An Assassin?! Get him now!
 * Altaïr: I need to stop for a few seconds to overhear their conversation.
 * Civilian 1: ...fine silks... Kasira's shop... kids...
 * Civilian 2: ...fishing... lure must be... Also keep in mind...
 * Altaïr: This is it! Maybe I can find out where it's going to take place.
 * Civilian 3: Lucky man, Ayman! He was invited to this great party tonight.
 * Civilian 4: Really? How do you know that?
 * Civilian 3: He just told me. He's on the other side of the gardens. He usually takes a stroll through the gardens at this hour.
 * Altaïr: Ayman, right? I have not time to waste. Tell me where the King is having his party this evening.
 * Ayman: I don't have to tell you anything. Begone!
 * Altaïr: I'm not a for you to order around!
 * Ayman: Argh! I'll tell you! Just let me live! The party will be held at Lacoeur's villa, in the north part of the city! Don't kill me, please!
 * Altaïr: You've never met me. Why would I kill you?
 * Ayman: Y... Yes, of course! Never met you!
 * Altaïr: The entrance is heavily guarded, but it's the only way in.
 * Guard: Raise the bridge! We are under attack! Hurry!
 * Altaïr: Who are you?
 * Man: I'm a friend, Assassin. I work for the King but... I am actually of Kadar's ranks. You need help to get past the entrance. Those who built this castle ensured that there was a secret passage...if one needed to get in or out of the castle unnoticed. There are four stones that need to be pressed with something heavy...for the passage to open. Use your eyes, Assassin! But first, let me open this door for you.
 * Altaïr: What about you? Kadar said he hasn't heard from you in a long time.
 * Man: It's hard, now that Basilisk is around. He is always watching. Tell my master I am alright. I'll be with him soon. Good luck, Assassin.
 * Altaïr: That must be the passage that goes underneath the castle.
 * Altaïr: This door won't stay open for long. I need to reach it fast.
 * Altaïr: This must be Basilisk! The key, around his neck!
 * Basilisk: An Assassin! And one that reached me, before I snatched him out of this world. A challenge, finally!
 * Altaïr: Not really, Basilisk. I'm not here for you.
 * Altaïr: So long, Lord Basilisk. I have the key, that's all I wanted.
 * Basilisk: You!! Come back!

Outcome
Altaïr obtained the final key and headed to Hazad's shop.

Reference

 * Assassin's Creed: Altaïr's Chronicles