We still have not cracked the secret of Greek Fire, a napalm-like weapon of terror and unmitigated destruction unleashed by the Romaioi of Constantinople on besieging Arabs in the 7th century. In fact, it's possible that they didn't, either, at least after the time of its original deployment, as almost all of our knowledge of the substance is legend and literary legerdemain.

It's entirely possible that the unextinguishable incendiary formula, which kept the Eastern Roman Empire in business for so long, was itself a pale copy of the stunning invention of a single genius, Kallinikos, who took the true, original recipe to his grave.

While a more sober reading of the facts suggests it lived and died with the Roman Empire itself, until 1453, it's easy to imagine the horror faced by anyone assaulting the city walls or leaping aboard an enemy trireme, only to see that odd metal pipe extending directly above their heads:

"Siphons!" the old man said, as gouts of flame filled the darkness, pouring from the carved heads.

I stumbled backwards, the back of my skull cracking against the ground. Pain blinded me, and I clutched at my scalp, hearing my sword clattering on the stone. Hot blood wet my hair as fire spilled across the rock. As I tried to rise, it fulminated over my shins. ...

The old man walked forward as soon as the torrent receded. Drips of blazing light continued to drool from the stone dragons' beaks.

"Naphtha, lime and old bones," he said, without a hint of anger or fear. "Not Greek!" Marlow said from within, his voice falling to a stammer. "My own formula!"

The key to its effectiveness was its ability to continue burning under any circumstances, even on the surface of water, making it a "wet, dark, sticky fire," and a key maritime weapon.

Possible ingredients include sulphur, petroleum, quicklime, phosphorus, naptha and saltpeter. But this is only the first twist in the tale, as with incendiary chemicals, the method is just as important, determining how the precursor chemicals are stored, the logistics of transport, and how they are mixed and deployed in battle. Did greek fire ignite on contact with air, water, or naked flame? Were its fumes poisonous? How could such a devastating weapon remain a secret for so long?

To know the truth, however, would be to rob the mystery of its allure–like nostalgia and futurism, the journey itself is always more rewarding than the destination.