Conscience is that thing that tells you what right and wrong are. That obnoxious little cricket served as conscience for the little puppet, and taught him right from wrong. Your conscience nags you when you've fucked up and should make it right but haven't yet.
One does not ever have a "guilty conscious". One may be conscious of guilt, or have a guilty conscience. BUT NOT MOTHERFUCKING "GUILTY CONSCIOUS"!!!!!!!!!!!!
This grammar bitch report is brought to you by $FANFIC_AUTHOR, who has just comitted an Unforgiveable.
[Edit: Fic fixed. Author knows better; spell-checker didn't catch it.]