More of a mystery movie with some gratuitous horror elements thrown in; mediocre overall.
It starts with a woman having a nightmare in which her sex partner gets out of bed, goes into the room of her crying child, and kills it. She wakes up. Then, that man is dying in a hospital, spitting up blood. His estranged daughter arrives, and he manages to contact her through her dreams (I think), and he wants her to find out who killed him before his body entirely decomposes in its grave.
There's not too much mystery about who did it, or even how; most viewers will have figured that out long before it is revealed. I'm not sure the way he was killed would really have worked.
Anyway, the horror elements get in through: a gory autopsy, the recurring dream of the man killing the boy, a nightmare in which a plate of eggs turn into eyes which are then cut, and several shots of the decomposing man both in nightmares and actually in his grave.
I was a little surprised to see a dedication in the end by Fulci to Clive Barker! Interesting.