The play received 'mixed' reviews. = The play's reviews were 'mixed'. [=some critics liked the play, while other critics did not]
I accidentally 'mixed up' the two files. [=I put each of the files in the place where the other one should have gone]
He 'got mixed up in' a plan to destroy the government. [=he became involved in a plan to destroy the government]
(..) - Let go. - Let go! - Hey! Listen to me. Listen to me. The last thing in the world we need is them knowing you're mixed up in all this. - Mike is over there... - They haven't found him. Not yet, at least. - For Mike? - Come on, get in the car. (..)2016 TvShow: Stranger Things Title: Chapter Seven: The Bathtub Season: 1 Episode 7