Claire Ross (Ava Gardner) is a young woman traveling alone by train through the American Southwest. Recently widowed and emotionally fragile, she’s trying to start over, heading to Los Angeles to take a new job and leave the past behind.

But something about this journey feels off from the start.

In her sleeping car, Claire meets a seemingly friendly couple — Mr. and Mrs. Bracken — who take an unusual interest in her. They offer to share dinner, ask her about her plans, and seem a bit too curious about whether anyone is expecting her at her destination. Claire tries to brush it off, but her instincts start to scream danger.