The mirror looked perfectly ordinary once again, not a single hand in sight. There was water all over the floor, and as we approached the tub I was suddenly very afraid that the eel might have vanished too. Dad and Kate would say that I’d cut my leg shaving or something. They’d think I was losing my grip on reality and I’d start to think so too. Perhaps I might even begin to wonder whether they were right and that I’d never had a sister at all, that Rosie was just a figment of my imagination, that I was the one who’d been ill, that there was nothing wrong with the lighthouse, only something wrong with me… But when I pointed at the water, the great dark shape was still there, so big and thick and muscled that it filled up half the tub.

Kate let out a sound that was half gasp and half moan. “Oh my God!” She gripped my arm. “How did it get in there?”

When she fetched Dad, he said that it must have 241got in through the pipes and slithered out of the tap.

“But it’s as big as my thigh!” I protested. “How could it possibly have squeezed out of the tap?”

Dad pinched the bridge of his nose, looking suddenly tired. “I don’t know, Jess. Perhaps eels can make themselves really small in order to fit through gaps like that? It could be a sort of survival mechanism. A mouse can fit through a space the size of a pencil head, you know, and—”

“That isn’t a mouse – it’s a whacking great sea monster!” I shouted, suddenly losing my temper. I was just so sick of being doubted all the time, of no one ever believing me or helping me.

“Well, for God’s sake, what do you want me to do?” Dad snarled.

I didn’t think I’d ever seen him snarl before, and I didn’t get the chance to reply before he lunged towards me. For a shocked moment, I thought he was going to hit me – something else that had never happened – but instead he snatched the bin up from the floor and hurled it at the mirror so hard that it shattered into sharp little fragments that flew out all over the tiles in glittering pieces.

After what had happened with the hands earlier, 242I half expected to see people standing where the mirror had been, but of course there was only the curved brick of the lighthouse wall. For the next few moments, there was a strange, strained silence, although I kept hearing the mirror smashing on a loop inside my head. Dad looked more shocked than any of us and gaped at the mirror as if he couldn’t believe what had just happened.