Kevin Costner compensates for his lack of expressivity by taking roles that suit his range, underpinning his stoniness with the illusion of depth. It's fine when the plot supports him, but movies like Dragonfly set Costner adrift.
He plays a widowed emergency room doctor who receives what appear to be messages from his late wife via patients having near-death experiences. This is a post-Sixth Sense supernatural film where New Age platitudes stand in place of Gothic menace. Dragonfly isn't unlikable, but its isn't the least bit compelling either. Trusty actress Kathy Bates turns up in a cameo, and the ending slightly betters what came before.