Ciel "Yeah. So am I"
Sebastian stays at Ciel's side while thinking about the time Alois, much like Catherine's rival did with her earlier that day, came after Ciel. Now of course Ciel was able to defend himself and get away, but it still plagues him that he couldn't be there at the time, as Ciel was partially traumatized and out of it when he finally reached Sebastian's location, Sebastian having just entered that part of the house after having a head on battle confrontation of his own with Alois' butler Claude.
The young boy from earlier that day, the one that resembled Ciel, waits outside the doors and at the end of the hallway that Ciel's room is on.