Talk about a messed-up ending. Arthur never did anything to the woman in black, he didn't even know her when she was alive, but she kills his entire family anyway and on purpose. And check out that creepy ending:
I looked directly at her and she at me. There was no mistake. My eyes were not deceiving me. It was she, the woman in black with the wasted face, the ghost of Jennet Humfrye. For a second, I simply stared in incredulity and astonishment, then in cold fear. (12.24)
Even when all the creepy happenings are over and the main character has returned to normal life (supposedly), there's still an unexpected pull toward the real horror. You can almost hear the screechy violin music building up as Arthur looks at the woman in black and then has to watch the terrible accident with his beloved Stella and baby boy.
In a way, this ending serves the same purpose as that last scene in a horror movie where a hand shoots out of a grave. Think it's over? Think you've put the evil to rest? Think again. The studio has a lot riding on The Woman in Black II.