is rotten in Denmark

something is rotten in (the state of) Denmark

Something strange or suspicious is going on. The line comes from Shakespeare's Hamlet. Why is Katherine being so nice to me all of a sudden? I'm telling you, something is rotten in the state of Denmark. "Something's rotten in Denmark," the detective muttered as he looked through the surveillance photos.
See also: Denmark, rotten, something, state
Farlex Dictionary of Idioms.

something is rotten in (the state of) Denmark.

Prov. something suspicious is going on. (From shakespeare's play Hamlet.) Jim: Look, there's a light on in the office, even though it's way past the time everyone should have left. John: Something is rotten in the state of Denmark. Jane: I wonder why Fred is coming in so late every morning. Jane: Something is rotten in Denmark.
See also: Denmark, rotten
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • Denmark
  • something is rotten in (the state of) Denmark
  • something is rotten in the state of Denmark
  • protest too much
  • shuffle off this mortal coil
  • (something), thy name is (someone or something)
  • the lady doth protest too much, methinks
  • the glass of fashion and the mold of form
  • make (one's) gorge rise
  • make gorge rise