Continuity mistake: When Mrs. Maxwell, the head of the "Occult Society", is arguing with her husband Milo, watch her dish of tapioca. In the first shot, a profile shot, the dish is full. When the shot switches to a head-on shot, the dish is nearly empty. In the next profile shot, the dish is once again full and she's just then taking her first bite.
Continuity mistake: Outside the Simmons mansion, Luther and Mrs. Maxwell are standing by the gate. Closeup shot of Luther shows a bush behind him, being blown by a breeze. The shots of Luther and Mrs. Maxwell show Luther with the stone column of the gate behind him, not shrubbery, and no breeze blowing.