Dear Nathan Landy and Prof. David R. Smith, scientists/electrical engineers at Duke University, N.C.

I understand from scientific journals and hacks’ stories in dailies, that you are another step closer to perfecting the "cloak of invisibility," this time using a diamond-shaped device to help take things forward from previous unsuccessful attempts. Who can forget the Cloak of Slight Noticeability? The Now you See Me, Now You Still See Me Suit? And the infamous Stands Out Like a Worn Wig at a Wedding overcoat?

I’m told that building on research done in 2006, you have improved how the edges of their "cloak" work, allowing light to pass around an object without reflections so that the human eye can't see it. Light waves are bent around the object, making it appear not to be there.

I’m afraid you are a decade or two too late boys. I had a Cloak of Invisibility long before your half-hearted efforts. I purchased it, at The Necromancer’s Market, near the Elven port of Vissimilitude, for 350 gold pieces, a +2 sword and three potions of resurrection. The cloak was absolutely invisible to anyone and everyone else in this particular school of Dungeon & Dragons, and only came a cropper when I passed through a waterfall on my way to the Orcs’ Tavern, which turned out to be acid.

In all seriousness, I ask you… why? Why do you persist in attempting to perfect a cloak of invisibility? Mephistopheles made Dr Faustus invisible for a bit, and all he did was play some parlour tricks on women, and kick the Pope up the bum. Not much of a deal when you have to give up your soul at the end of your reveries. Are you pair so geeky that you want to play Harry Potter for real?

Come on, the only thing that a cloak of invisibility can be good for is some low-end wheezes and merry japes, that both you and those who were subject to them will tire of in a week or so.

Then I saw the bit at the end of the article and it all fell into place:

“The research was partly funded by the U.S. Office of Naval Research and the Army Research Office.”

It’s a military thang y’all. It’s to get drone technology upgraded to real thinking people doing the drone killing, up close and personal, but then walking away unseen. I should have realised. Sorry. Carry on. I’m sure it’ll be used as a weapon of the Light against the forces of Darkness and Oppression. But I bet there’s a person already working on a cloak of All-Seeing that will counteract the Cloak of Invisibility. Sponsored by some other military power no doubt. I think I preferred my Dungeons & Dragons. Bye for now, must fly… and remember .. “You ain’t seen me, right?”