A terrifying moment

Marion was standing still. At Hilary's question she seemed to become something more than still. Where there is life there is breath, and where there is breath there is always some movement. Marion seemed to have stopped breathing. There was a long, frightening minute when it seemed to Hilary that she had stopped breathing. She stared at her with round, terrified eyes, and it came to her that Marion wasn't sure - wasn't sure about Geoff. She loved Geoff terribly, but she wasn't sure that he hadn't killed James Everton. That seemed so shocking to Hilary that she couldn't think of anything to say or anything to do. She learned back upon her hands and felt them go numb.

(from The Cased is Closed, by Patricia Wentworth)