Hamilton's story, told in a non-linear style - mostly just standard flashbacks, has a lot of emotion and melodrama written into what is otherwise a stereotypical "paranormal transplant thriller". Not that it isn't a cool horror trope, and WDLB has some good moments in it, it is just a concept that never seems fully exploited to the movie's benefit.
The story moves to slow and there is way too much use of psuedo exlressionist visual techniques that - together- cause quality sceens to expand beyond necessary, creating loss of momentum. It exposes flaws in acting and dialog that with proper post attention could have spared "What Death Leaves Behind" a loss in suspense. The pace, focus on emotionality and over-tapped scenes keep this one from being as thrilling as it needed to be.
That being said, the film has some quality moments. For most of the film everything rides on newcomer Khalil McMillan's performance, and he does a good job. Actually the cast on a whole give stellar perfances during a lot of the film. Unfortunately though there is a lack of consistency and a few times the dialog is a mess. But again, there is some quality talent at work in front of and behind the scenes in WDLB.
As far as horror goes, this film never really reaches that level necessary to create the chilling nature of the story. It tries hard but suspense gets bogged down by emotional theatrics to often, and the surrealism is just too much at times. More attention should have been spent on action and stronger, edgy psychological elements. Film like "The Eye" and "Body Parts" did this premise better. Overall "What Death Leaves Behind" is one worth checking out, just go in without expectations.