MISS PETRIE - a pleasant, efficient woman in her fifties with a genuine liking for people.
DR. ROY FLEMMING - a polished, urbane New York psychiatrist in his forties. Highly civilized, pragmatic, with a cold, functioning intelligence. He wears conservative, artfully-tailored suits.
CLAIRE FLEMMING - a brittle, sardonic product of New York's East side. She is in her early forties and shows the strain of a loveless marriage.
SUSAN HUDSON - Young and extremely attractive, with a hint of latent sensuality. She is not particularly complicated, but as the play progresses she shows the burden of the increasing tension.
LIEUTENANT COLUMBO - a rumpled police official of indeterminate age. He seems to be bumbling and vague, with an overly apologetic, almost deferential manner. This masks an innate shrewdness, and foxy knowledge of human nature.
DAVE GORDON - a smooth, boyish lawyer with his eye on a political future.
DELIVERY BOY - early twenties.