There is a shark in our local swimming pool. It cruises beneath my nine-year-old, jaws stretched in anticipation of her flailing heels. Back stroke is deadly for the shark, undetected, threatens to swoop from the depths and clamp her from behind.
The most dangerous thing about the shark is that it is invisible and therefore unavoidable. She knows only that it lurks somewhere in those turquoise depths awaiting her.
Each week, nonetheless, she returns from her swimming lessons with flesh unscathed. But new perils must be faced at home for there are monsters in her bedroom. They unfurl when the lights are dimmed - nightmare shadows on the wall. The fluffy pink dressing gown hanging off the doorknob morphs into a hunchback; the light with its shade, a crone in a witch's hat, and invisible horrors issue through the black slit where the wardrobe doors don't quite close.
'Nonsense!' says the Vicar who doesn't believe in hauntings. But I have lived with monsters too. Their forms shift with age. Bathrobes and lampshades no longer terrorise me and I am brave about cracks in cupboard doors. My monsters lurk on motorways waiting to engulf my children if they travel without me. They take shape on the landing if my wee ones sleep in longer than usual. They leer at me from the depths of the future in which nameless horrors may be skulking.
I must therefore be patient about the shark even though, from my superior vantage point, I can see that that the scary deeps are empty.