lose the plot vs unseat

lose the plot

verb
  • To cease to behave in a consistent and/or rational manner. 

  • To lose sight of an important objective or principle; to act contrarily to one's own interests through concentrating on relatively unimportant matters. 

  • Used other than figuratively or idiomatically: see lose, plot. 

unseat

verb
  • To cause something to be removed or replaced in its role; to displace, overturn. 

  • To upset the composure of (in various ways); to astound, shock, or unsettle. 

  • To remove from some (especially political) position or office; to dethrone. 

  • To come out or off of a seat. 

  • To remove or dislodge from a seat (especially referring to horse riding). 

How often have the words lose the plot and unseat occurred in a corpus of books? (source: Google Ngram Viewer )