The Ability to be made Invisible when Heated

Since time immemorial the Marshalls had governed over the barracks of Basingstoke. Deep in its soil was buried a mysterious substance there - a metal called Misery - that had not yet been identified or known to men, although it had been refined and crafted by Fey from ages past.

The whereabouts of this metal had been so well concealed that humanity had not yet the chance to know of its properties, or even its existence.

Misery had several characteristics unlike any other. Firstly its conductivity was superior - over a thousand times more conduit to that of the finest silver.

Secondly, it was more malleable than gold, with a tensile strength that was plant-like and fibrous in structure and capable of keeping memory within its internal weave.

Thirdly it bore the ability to be made invisible when heated and then to reappear when charged anew. This gave it many applications of usefulness - especially in armour for which it was impenetrable, and as a compass, impeccable.

To have a substance that could become invisible worked in many ways quite well. You could conceal items within a box made of the metal (or a wall for that matter), but be able to see into that space when needed - or conversely, one could wear a finely spun suit of it and be both hidden and shielded at the same time.

It was named 'Misery' - some said because of its endurance, or possibly because of the Miser's love for keeping it to themselves.

There were a few such oddities that the Fey had held secret from the World at large. Because of it they could hide practically anything in boulders, in the ocean or mountain's heart.

-Gabriel Brunsdon, Puck in Hell, Azlander Series