"You want to stab the man, under the theory he'd be as likely to notice a needle as a knife. That oversimplifies. What about a needle in his clothes, I doubt he washes his own, or repairs them himself, getting pricked by a needle you find in your clothes fresh back from getting mended hardly causes alarm, for instance, just irritation. He also probably doesn't take his meals with others but has them sent to his rooms, poison could get him that way. Even if he doesn't get a lethal dose it would be easier to kill him afterwards. One does not simply stab someone in the Fortress of Light. There are hundreds of wary and trained fighters roaming it's halls at all times. Outside of the dungeons, you can assume a scream will bring a rapid and armed response. We also would be better off preparing a scapegoat. Preferably a faction in the whitecloaks who dislike this new adviser and are known to do so, that way if we fail it will not only not point at us but could actually cause that faction to try to kill him for real, should accusations fly. Regardless, if the situation can be set to point at a powerful faction amongst the children, like the questioners, this man may flee the fortress, making our job easier. I don't think just gutting the man in the hallway is a wise idea. Let us try to be a bit more subtle"