I... [His voice, even his hands shake, the gun sight not steady at all as he points it at Sebastian. He doesn't understand why Sebastian isn't remotely scared by the firearm he's pointing his way, doesn't understand what other use Sebastian would have for him if it isn't in the pursuit of money.
Stop it, stop it, STOP ADVANCING ON HIM, stop acting so cavalierly towards the deadly weapon he's got trained on your heart. When Sebastian doesn't stop, when he crosses that line, the space Ciel drew in his mind as being too close for his safety, his finger jerks on the trigger, eyes squeezed shut and shot sent wildly over Sebastian's head. The shock of the recoil bounces the gun around and through sheer luck, the second and third shot slams into Sebastian's chest. The fourth grazes his temple and at the sight of that much splattered blood, Ciel sobs and halts, tightly clutches the gun to his chest, horrified that he's actually killed someone.