Ellery Queen : Dad, why does the coffee always taste better in your office than at home?
Inspector Richard Queen : Because my secretary doesn't make coffee at home. You do.
Grace : [entering] Excuse me, Inspector, but...
Inspector Richard Queen : Oh, Grace, if you have a chance, Ellery would like to jot down your recipe for coffee.
Grace : [puzzled] Uh... it's only coffee and water.
Inspector Richard Queen : [to Ellery] Which one of these ingredients is it that you leave out at home?