Finn hates water. She's haunted by terrifying nightmares in which she is running before a huge wave that threatens to engulf her in watery darkness for ever. And the dreams have been worse since she, her mum and her two younger brothers arrived in Cornwall. Then she discovers the strange curse that was laid upon the cottage years ago, and she's sure vengeful Griffiths has something to do with it. She's seen him, endlessly tying and retying a length of rope, creating the knots that - superstition has it - can conjure storms. Finn knows that she's in mortal danger if she can't find a way to break the curse...