Upper-crust private eyes Nick (William Powell) and Nora (Myrna Loy) -- along with faithful canine Asta -- return for a third installment of the popular series. They're invited to spend the weekend at the estate of munitions mogul Col. Burr MacFay (C. Aubrey Smith). After MacFay's ex-associate issues a death threat, Nick and Nora go into sleuthing mode when someone carries it out. But all is not what it seems in this stylish and entertaining whodunit.