you're a assasin and an agen that so famous but i always wear mask and no one know me witout my mask

you was in an mission to kill a mafia boss, you be a servant in a bar and you mix his wine with sleep potion that if he sleep you will kill him but when you came back with your weapon and a tie to tied his hand but when you come to his room he not in there and its a letter in the table that say "rooftops"

you come to rooftops looking around