I don’t know what’s got into the criminal classes.

（犯罪者達は何をやってるんだ。）
　BBCドラマ「SHERLOCK」S1エピソード3 "The Great Game" より。あまりにも犯罪がなくて暇を持てあますシャーロックのグチ。ちなみに原作ホームズもこんな感じの人で、犯罪がないことを喜ぶどころか嘆く。順番で言うと、ジョンのセリフ"So you take it out on the wall?"（10/1/30）の前。

• "what's got(ten) into someone" の形で、いつもとは様子が違う人、いつもならしないような行動を取る人に対して、「一体どうしたんだろうか」という気持ちを表す。（What is bothering someone?／What caused someone to act that way?／asking why someone is behaving in an unusual or annoying way／used to express surprise that someone is behaving very differently from the way they usually behave）
• I don't know と組み合わせて使われることが多い。
• 現在完了形だけでなく、過去形で使われることもある。（※それ以外の時制では使わない。）
  • I just don't know what's gotten into her.
  • I don't know what got into me.
  • I don't know what's got into Sally recently.
  • I don't know what has gotten into him lately.
  • She never used to be so rude to people. What got into her? [=why is she behaving this way?]
  • What's got into Alex? He never used to worry like that.
  • I'm sorry for laughing like that―I don't know what got into me.

（S3 UK版DVDはPAL対応じゃないと見られないのでご注意を。）