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.
(..) You really think that Ford has entrusted you with a key character for his story? He's already almost finished with it. He dug up some old town on the fringes of the park, created a horde of masked men to terrorize guests and proselytize-cum-advertise the coming of some end-all (..)2016 TvShow: Westworld Title: Trace Decay Season: 1 Episode 8