Note: I believe Sivert is the first assassination Arno does, but I'm too lazy to double check. Please bear with me if I'm wrong, this is an AU anyway.

-/-

His first assassination is plotted on the rooftops across the street from Notre Dame Cathedral, as the streets below him echo with the voices of the people passing by. On his left, Bellec is short tempered and stern faced, making no secret of his impatience with Arno's hesitation. On his right, Altair is an only half visible specter, impassive and patient, bright eyes gleaming in the shadow cast by his hood as he surveys the situation.

It is difficult to imagine a more dissimilar pair, for all that they should be agreeing. Sivert is an unpleasant man, a templar, and the only way Arno has of finding out why Elise's father had to die. But Bellec seems to only care about his allegiance, while Altair is at least aware how badly Arno needs to know why de la Serre is dead. To the casual observer, Altair seems flatly uninterested in the context of the assassination, but Arno is used to having the man in his head rather than seeing him as this half transparent ghost at his side. He can read Altair's body language as well as his own, and he's clearly aware of the backstory here.

"Create an opportunity," Bellec says, voice cold and almost angry. "If there is no good chance for an assassination, change the odds to benefit yourself."

"Search the area," Altair says, expounding on the other man's terse advice. "Find an opening. There are hundreds of people in this crowd- someone will know a way in, and if they are careless you can take advantage of their entrance."

"There's a man that stole a key," Arno says, eagle vision stretched as far as he can make it go. "If I could take it from him, I could get inside that way."

"Good eye," Altair says, although, Arno is convinced the older assassin must have already seen it.

"Sure," Bellec scoffs. "If you can get at the key. We'll see."

Arno frowns at him. "Do you think I can't do this?"

"You haven't yet," Bellec points out. "Just remember- the bottom line is that this man is your target now. You are responsible for his death, no matter what you have to do to make that happen."

"No matter what..?"

Bellec wears no hood, an odd choice from what Arno has seen of other assassins, and so there are no shadows to hide his oddly flat smile. "In the days before Altair-" he pronounces the name in a way that's just slightly off- "Self-sacrifice was the tactic of choice."

"A knife in the middle of a crowd, you mean?" Arno asks. "An assassination in broad daylight."

Altair rises from his contemplative crouch, shooting an invisible glare at Bellec that the man completely overlooks, given that he can't actually see Altair. But Arno sees it, and even though he's not the one Altair has chosen to direct his anger toward, he shivers and has to fight the instinct to step backward, like a helpless animal running from a predator.

"This man," Altair says, clearly addressing Arno even as he continues to glare at Bellec. "Is a charlatan. He wears the robes of an assassin, but acts with no regard for the safety of the men he should be claiming as brothers. We changed that practice for a reason, hundreds of years ago." He turns away from Bellec, an expression of absolute and complete disgust on his normally inexpressive face. "Don't trust him," he warns Arno. "Don't."

"Well?" Bellec prods, and Arno starts as he realizes that from Bellec's point of view, Arno has just been staring intently at nothing. "Get a move on."

"But I-" he's never killed anyone, not like this. A few guards, in the Bastille as he escaped with the other prisoners. But not an honest assassination, like this. He doesn't know what to do, or if he will even be capable of the final act when the time comes.

Altair sees his face, and the anger fades away into a kind of sad sympathy. "I will help you," he says. "If that's what you need from me."

He nods, one sharp motion because Bellec is still watching and Arno cannot let him think him crazy. The man is already suggesting he commit suicide on his first assignment. Insanity will not help his transition into the strange new world that is now his life. Altair puts his hand on Arno's head, and without a single word begins to push. It's a funny feeling, but not one that Arno is unused to after his time with all these people in his head.

Arno lets it happen, and then there's a feeling of weight in the back of his mind, a second person settling into place in his thoughts. "How am I supposed to kill a man?" he asks. "I've learned… technique. Fighting. Blades. But-"

"Actually killing someone is different," Altair agrees. "I know."

"But you've killed people."

"Everyone has their first," Altair says. "And no one knows what they're capable of until the moment they see their target face to face. Some people can kill. Some people can't. Some only kill in the heat of a fight, because they can't stand watching the death. The life bleeding out of them."

The image of a man bleeding out in front of him will not leave Arno's mind, no matter how hard he tries. He shudders and shakes his head. There is something in his stomach like a wiggling, painful snake, a serpent coiled and waiting to bite. He is afraid.

"Take it one step at a time," Altair says. "Start by finding a way inside."

"Alright." Arno says, courage bolstered a little by the calmness of Altair's tone. He can do this.

And he does. Getting himself inside the cathedral really isn't difficult. Arno has had training, after all. Once he's inside, creeping around in the rafters, Altair prompts him to the next step.

"Now look around. Identify your target. Find out if there are significant obstacles between you and him. Look for guards, and know where the innocent bystanders are. Watch his pattern of movement. Try to predict where he will be before he gets there, and be there first. Decide if it will be possible to take him out without being seen. If not, thin the ranks or prepare for a fight."

"…the confessional," Arno says, after several minutes of careful observation. "No one will notice he's dead until I'm long gone."

"Yes," Altair agrees. "Now the next step is to actually do it."

Right. Just… get down to the main floor, get into the confessional, and then… kill a man in cold blood. Easy. Just one quick stab, and it will all be over. Bellec will be satisfied, and Arno won't have to deal with his comments next time.

He's actually in the confessional by now, shaking like a leaf, trying to convince himself that this is the right choice, that somehow killing this man will make the world a better place. Even knowing that he was involved in de la Serre's murder doesn't help, and for the moment at least he is terrified into frozen indecisiveness.

In other circumstances, he would have been able to figure this out, push down his emotions, and just keep going. He would have killed Sivert, because at this point there is clearly no going back.

But he hasn't quite managed to screw up the courage to do it yet when his arm moves on its own, and his hidden blade comes out, and there is blood on his hands, and Sivert is dead. Arno watches through disbelieving eyes as he draws the blade back and wipes the fresh blood away in an easy, practiced motion that doesn't feel like his.

"Calm down," Altair says, and Arno forces himself to listen.

"Did I just do that?"

"No," Altair says. "Sorry. I did. I had to borrow your body."

"That's alright," Arno says, relieved in a way that makes him feel heady and light because it hadn't been him that killed Sivert in that practiced and mechanical way.

"You should leave now," Altair says. "Someone will notice his death soon enough."

Arno nods, because escaping is something he can do. He can run, climb, disappear into the shadows, and he can do all this much more easily than he can purposefully take a life. It's not until he's safely away and on the streets several blocks away from the cathedral that he addresses Altair again.

"Thank you," he says. "I completely froze."

"I understand."

"I don't," Arno says, more dejectedly than he'd meant. "I completely froze. I was afraid, or something."

"I know," Altair says. "I'm in your head, remember? I felt it all. But I wouldn't worry. You weren't ready to kill. There's nothing wrong with that."

"But he killed the father of the woman I love!" Arno protests. "I want him dead! Why couldn't I kill him?"

"There's a long gap between wanting a man dead and wanting to take his life yourself," Altair says. "There's nothing wrong with being unable to kill. I would have been more concerned if none of this bothered you."

But Arno still feels like a failure, like he isn't worthy of the title assassin if he can't technically assassinate anyone. He swears to himself that he will be better the next time. That he will be able to kill the next templar that crosses his path, no matter what.

He's very afraid that he's lying to himself.

-/-

I've always felt like Arno's personality makes him a very poor fit as an assassin. He would have been way happier if he married young and had half a dozen babies instead.