The detectives 'dug into' his past and learned that he had once lived in another country.
Her fingernails 'dug into' my hand. = She 'dug' her fingernails 'into' my hand.
The salesman 'dug in his heels' and refused to lower the price any further.
(..) I don't think I can risk it. Manny, please. I have too much to worry about right now. - Okay? - You? I dug a pretty big hole for myself with those insult jokes this morning. Why didn't I learn from Rickles? You gotta end with some ticker. Okay, I give up. (..)2012 TvShow: Modern Family Title: Bringing Up Baby Season: 4 Episode 1