How to utterly terrify a small child

I made an offhand joke on holiday to the kids that had unforeseen consequences. I’d made some toast for breakfast and for once hadn’t burnt it. I even remembered the jam goes on after you’ve toasted it. However for some reason my unburnt toast set off the rather sensitive smoke detector in the hallway. Beep Beep Beep went the detector with some gusto. The kids appeared in a rush and asked what it was. At home when the smoke alarm goes off, there’s usually a thick haze of smoke clogging the air so they were somewhat confused.

“It’s the ghost alarm.” I said, for no discernible reason, other than it sounded a good wind up. Two huge pairs of wide eyes stared back at me. Wifey stepped in for damage limitation. “No, it’s just the smoke alarm, Daddy’s being silly.” Two huge pair of eyes continued to stare at me, “Where are the ghosts Daddy?” “Well, they’ve gone now, that’s why the alarm has stopped, so I doubt we’ll see them again.” I said.

And that was that. Or so I thought. The other night, at about 4am, the bloody battery in one of the smoke alarms in the kids room started running out, eliciting a regular beeping that was loud enough to wake the kids up and instill a primordial terror in them.