The play explores the worst thing that can happen to a marriage on the edge, when a couple, Ethan and Liz, become stuck in a car one winter on a deserted highway. Forced to cooperate until help arrives, they confront the issues that have undermined their marriage: his long hours at work, her history of depression, their emotional and physical estrangement, and the recent death of their son and who, ultimately, is to blame for it. At times droll, at times savage, Couldn't Say shows two characters in a battle for their lives, trying to survive until help arrives.