Sorry, Wrong Number (1948) review

Confined to a bed because she believes she has a heart condition, Leona Stevenson (Barbara Stanwyck) tries to phone her husband Henry (Burt Lancaster) at his office except he's not there and instead she hears a mysterious conversation about a planned murder, so she's consistently on the line with multiple people: the police, "rival" Sally Hunt Lord (Ann Richards), dodgy chemist Waldo Evans (Harold Vermilyea) and her own father James Cotterell (Ed Begley), a pharmaceutical manufacturing giant.  Lucille Fletcher adapted her successful radio play to the screen and added so many flashbacks - and, in one instance, a flashback within a flashback - that it's told in a frustratingly roundabout manner (although they are sure keeping those switchboard operators busy).  Lancaster's character is perpetually surly (and since he'll probably take over the business eventually it's unclear why he'd try to sabotage himself) and while Stanwyck is fine, she has to act terrified every moment she's on-screen.  The Master of Suspense might have been better suited to reshape this into something smoother - his Dial M for Murder is very good - but at least it has the nerve to leave the audience with a downbeat ending.