The museum was recently 'plunged into' scandal when it was learned that some of its art had been sold on the black market.
We've been thinking of buying a new car, and yesterday we finally 'took the plunge'. [=we bought a new car]
A series of bad management decisions are responsible for the company's 'plunge into' debt.
(..) Jeff, you know if someone came in here, they wouldn't believe what they'd see. What? You and me with long faces, plunged into despair... because we find out a man didn't kill his wife. We're two of the most frightening ghouls I've ever known. You'd think we could be (..)1954 Rear Window
(..) Thank you. There's no more stars. Is it time? Yes. It's so quiet. It's the deep breath before the plunge. I don't want to be in a battle... ...but waiting on the edge of one I can't escape is even worse. Is there any hope, Gandalf, for Frodo and Sam? (..)2003 The Lord of the Rings: The Return of the King
(..) letting the bad guy get ahead. One day... you may face such a moment of crisis. And in that moment, I hope you have a friend like I did... to plunge their hands into the filth, so that you can keep yours clean! Your hands look plenty filthy to me, commissioner. We take Gotham from the corrupt! (..)2012 The Dark Knight Rises