Phantasm

Teenager Mike lives with his older brother after his parents die in an accident. Mike happens to observe the Tall Man's strange activities in the cemetery. No one believes his observations, so he secretly investigates further and discovers that the Tall Man, guarded by his flying orbs, is shrinking human bodies in the mortuary and preparing them for transport to another dimension. Before he can inform his brother, Mike is discovered and pursued by the Tall Man.