As you infiltrate the city, you slip through the gates completely unnoticed in your Altair vest. If the guards knew your intentions, they would hunt you down like a murderer. Fortunately, today no one knows that you have that mission.
He finds his target when he enters his hideout, two of his guards at his side. There may be a way to get in undetected, and that's when you see the open window on the third floor. That won't be too difficult to achieve. Not for a skilled assassin like you.