This paper-waster (by the unrepentant author of 1976's nadir, The Plants) will be promoted as an imitation Exorcist, but it really derives from one of those low-budget vampire movies--in its stilted dialogue, its vaguely turn-of-the-century European setting, and its dum-de-dum-dum, by-the-numbers plotting. On a vacation in Bavaria, the six-year-old son of properly English Anna and Edmund dies of a causeless fever, and the strangely unblemished corpse comes to life during the night and strangles governess Edith. He's a possessed Moonchild, you see (according to an old crone and a mad doctor from Central Casting), and unless Anna and Ed can bury the kid at his birthplace before his seventh birthday, his soul will remain bloodthirstily restless, his corpse will turn into a hairy monster, and he'll claw-kill anyone in sight. Fair enough. So Anna and Ed lock him in a jeweled casket and flee for England by carriage and rail, pursued by Inspector Fuchs, who thinks that they're escaping criminals. Along the way, various fools open the casket and get a claw in the throat, and everyone screams things like ""God in Heaven . . . It is a monster."" For a while, however, daddy Ed is unconvinced, saying, ""I do not believe a word of this. . . rubbish."" Neither will anyone else.