Imagine if Lewis Carroll had written the screenplay for The Babadook and you sort of get The Skriker, Caryl Churchill’s wordy folk-horror play about postpartum depression. The 1994 eco-revenge fantasy is about two sisters fighting off a fairy that feeds on wishes. It’s technically ambitious, but Contemporary Theatre Company’s outdoor production is mostly successful, particularly at sundown on a brisk late summer evening (although the lady sitting next to me disagreed, ducking out before the end). The play’s success depends entirely on the title character, or more exactly the actress required to remember pages and pages of jabberwocky-ish monologues. Thankfully, Christine Cauchon pulls off all of Churchill’s linguistic tongue-twisters without looking like a showoff or sounding like a beatnik poet. A couple of giant puppets and two musicians add to the play’s spooky feel, though the biggest nail-biter is the show’s combo of open flames and loosely flowing fabrics. Go, but wear layers.