look around vs step in

look around

verb
  • To take note of what is going on; to make oneself aware. 

  • Used other than figuratively or idiomatically: see look, around. 

  • To turn one's head to see what is behind oneself. 

  • To inspect a building or area. 

  • To search a place. 

step in

verb
  • To get involved; to act 

  • To act as a replacement or substitute. 

How often have the words look around and step in occurred in a corpus of books? (source: Google Ngram Viewer )