The Slow Torch

It is a lovely object. Machined aluminium, knurled grip, a switch with a click you can feel through a glove. You press it in a dark room and nothing happens. Three seconds later the beam arrives, lighting precisely the spot the torch was aimed at when you pressed, which is by then a spot of no interest to anybody.

Nobody asked for this, because a torch is an instrument of now. Sweeping it across a dark garden produces a lagging circle of light that reaches each bush just after you have given up on it, so the entire walk becomes a calm, well-lit account of everything you have already passed.

And yet it does one thing no other torch can. It is the only light in the world that shows you what a room looked like three seconds ago. Point it at the kitchen counter, wait, and you will see the counter as it was before the cat heard you coming. Owners are unanimous that this is not a novelty but evidence.

It carries a five-year guarantee, which the makers can offer confidently, because nobody has ever used it twice in an emergency. It lives in the drawer, comes out at parties, and has been aimed, thoughtfully, at a great many doorways where somebody had just been standing.