At once I was sucked into this tale for it's light atmospheric effects and it's heavy, though lightly painted, themes of myth and classic horror tales rolled into a singly well-drawn story. 
 Classic horror themes abound, of always paying the dead their price, tying the Osiris/Isis story to old Irish legends, only to be tied to the christian by the end. 
 It's perfectly reasonable to tie christian characters back to a christian moral, of course, and the images and the feelings of awe and its reverse were quite delightful. I was reminded of what could have been a truly classic ghost story with risen zombies and resurrections all placed nearly a century ago more than a modern tale of horror. The time and place lends itself fine for that interpretation, with daddy going off to fight in a world war to leave the children and mother behind. Alas, not a problem. It's classically written, classically told, with a deft touch with all the myths bursting out from every page. 
 It's also scary, and delightfully so, with particularly good characters filled with complex psychologies and loss. 
 It was a great setup and even though I am fine with the christian interpretation, I find myself wistful and rather having wished for an actual Isis/Osiris theme to come home to roost. But still, I find no faults with how it actually turned out, because it was very effective.