Rose Lorkowski (Amy Adams) is a thirty-something single mother, working full-time as a maid. Her underachieving and unreliable sister Norah (Emily Blunt) lives with their father Joe (Alan Arkin), and is fired from her job as a waitress. Rose's hyperactive and disruptive 8-year-old son Oscar (Jason Spevack) upsets his school officials by his erratic behavior, and they order Rose to put him on medication or send him to a private school. Unable to make enough money with her current job, Rose asks Mac (Steve Zahn), her ex-boyfriend during their high school years and her married lover, for advice. Mac recommends a crime scene cleanup job, and with his connections as a police officer, he gets Rose and Norah into the business.