I must confess that I have not seen anywhere near as many Italian movies from the 70s and 80s as I think I have, since I keep stumbling across previously-unviewed giallos -- so-called from the yellow dustjackets of thriller novels. I had vaguely heard of this film from director Pupi Avati (a minor horror director of that time) and probably remembered it because of its unusual title, but I had certainly not viewed it previously. Unfortunately, despite its fairly respectable cult reputation, it was not in my opinion much of a find.
It stars Lino Capalicchio whom I recognized immediately from the far superior arthouse film "The Garden of the Finzi-Continis" (1970). He plays an art expert who is employed to restore the altarpiece of a church in a remote town. Something should have alerted him immediately that all was not right, since the death of St. Sebastian was depicted here by knives (while as anyone with even a cursory knowledge of religious painting knows, the saint was killed by arrows). He might also have had further suspicions that the town harbored secrets by the succession of weird folk he encounters (a dwarf mayor, a slightly subnormal local lad, a paralysed old woman, an overly-cheery priest, et. al.) and by the fact that the friend who summoned him there soon meets his maker falling from a high window. He learns that the dead painter of the original fresco had death-cult leanings, encouraged by his two very strange older sisters, and that various suspicious disappearances accompanied the fresco's original conception.
This may make the film sound somewhat appealing, but I must tell you that the story unfolded in a more than slightly incoherent manner, aided by abrupt transitions between scenes. It did manage to convey a growing sense of dread as our hero attempted to solve the mystery of the painting's history, especially after his restoration was well and truly trashed. However the supposedly shock ending was too clearly signalled in the build-up and I found myself wishing that a more talented director might have used the bare bones of this story in a more compelling and suspenseful way. Oh yes, when I was beginning to think that the house of the title had no relevance, we were allowed to see the side view of the house where the old painter and his sisters had lived, with its large grinning red mouths painted across the panes -- not that this really had much to do with anything! It did, however, provide for a good "come-on" title for a frankly very flawed movie.