Kip. 9: His Butler, Serene
As the other Phantomhive servants dispose of the intruders, Grell appears to collect their souls and becomes disappointed upon not meeting Sebastian there. This later turns to anger after Grell discovers (through watching Beast's cinematic record) that Sebastian seduced her. Back at the Kelvin estate, the doctor from the circus appears before Ciel and Sebastian, revealing that the prosthetic limbs he developed are manufactured using the bones of the children kidnapped by Joker and the others, and Joker himself suffers a mental breakdown when he learns that his artificial limb as well was produced in such way. When the doctor kills another of the children in front of Ciel, the Earl (having painful flashbacks) orders Sebastian to kill him, and (opposing to the queen's orders to rescue the children alive) commands his butler to burn down the entire mansion, killing the captives as well. (Source: Wikipedia)