The Butler, Chastised is Chapter 142 of the Kuroshitsuji manga.
Summary
Othello announces, as they have finally found their target, it is time for the "spanking" before saying to Undertaker that William T. Spears told him everything about him and that he is very interested in Undertaker's experiments and would like to look into his messed-up brain. Undertaker replies that Othello is the last person from whom he would like to be told that he has gone insane. Then, Undertaker asks what made Othello, as reclusive as he is, come out.
Taking out his Death Scythe, Othello states that he could not focus on his research due to Undertaker's doings and will not punish him for this. He throws his scythe, but it does not get anywhere close to Undertaker, and Undertaker starts laughing hysterically, saying that Othello is still as physically weak and useless as ever. And Grell loudly expresses their surprise as they have believed that Othello was one of those persons who only pretended to be weak but were actually very strong. Othello only says that he has always told them that he was not very strong and that they should attack Undertaker now.
Recovering from his laughing fit, Undertaker stands up and takes out his own Death Scythe, demanding the other Grim Reapers to leave. Upon seeing Undertaker's scythe, Othello hides behind Grell and begs them to protect him as he does not want to die. Grell is not very amused about the fact that he is using them as a shield. They then jump to attack Undertaker as they were eager for a rematch since their fight on the Campania.
However, before their fight can actually start, Sebastian interferes as he does not want Phantomhive Manor to be damaged. "Ciel" chuckles at Sebastian's words and says that he is the master of the house and that he demands Sebastian to leave.
Right afterward, Scotland Yard marches into the manor. Edward and Alexis are with Fred and the officers. Fred says that they received an anonymous tip, stating that Blavat Sky and his conspirators are hiding in Phantomhive Manor, and now, he would like Ciel to explain himself. He then notices that there are two Ciels and is very confused—and so are Edward and Alexis.
Cheerfully, "Ciel" greets Alexis and says that he has finally come home, only to find out that Ciel stole his identity. Alexis and Edward stare at Ciel who gets more uncomfortable with every passing second. Then, Elizabeth arrives at the top of the stairs and verifies "Ciel"'s words, saying that he is not a liar—but Ciel is.