My Cousin Rachel (1952)

When Philip Ashley's much-loved (and rich) cousin Ambrose dies, he is convinced that Ambrose was murdered by his new wife Rachel to inherit his wealth. But when he meets Rachel and falls in love with her, he knows that his suspicions must have been unfounded. But were they, or is Rachel just trying to use Philip to get at the estate Ambrose left to him instead of to her? And will she murder him next?