If you get off on watching things go bump in the night – and who doesn’t? – then The Babadook is the scarefest for you. Here’s the setup: Amelia (Essie Davis, outstanding) is a nurse and widow who lives quietly with her six-year-old son, Samuel (Noah Wiseman), an impressionable, fatherless kid given to acting out. Making Samuel worse is the mysterious arrival of The Babadook, a monochrome pop-up book (designed by Alex Juhasz) about a mysterious dude who knocks three times at your door and . . . well, I’ll never tell. Let’s just say that this nerve-frying psychological thriller from gifted first-time filmmaker Jennifer Kent will have you climbing the walls simply by plumbing the violence of the mind. Brace yourself.