The person who gave you that mission should have been surrounded by them. They will have been non-functional (in that they don't fight back), and they get up again after you put them down. You only have to knock one to zero health before talking to that person again and moving on.
the problem is its come no 1 around the person who give me the mission!
i just starting the game and the first mission in the tutorial is "find and destroy 1 clockwork" but i dont find any!!!! anh many new players have the same problem as me!! some 1 please answer thx