A Load-Bearer is seen as a great arch or buttress of stone, bent like a back under a burden, with two or four broad limbs set against the plane’s rock and its shoulders against another mass of stone above. Its stone is darker than the Foundations', nearly black, and veined with copper that glows brighter where the weight is greatest. It shifts very slowly, over days, as weight moves, with a sound like the deep creak of a ship’s timbers. It is warm to the touch.

They stand in the deep structure of the Iron Backbone, between its islands and its Foundations, wherever weight must be moved from one place to another.

A Load-Bearer bears and passes on. It takes weight from where there is too much and moves it to where it can be carried. In the Backbone weight follows significance, so a monument of history is impossibly heavy, and the Load-Bearers seem to shift towards whatever has just grown heavier.

It carries and spreads weight beyond any measure, and can ease the weight on what is near it.

They keep the Backbone from cracking. A traveller crushed by the weight of the plane is sometimes said to have been saved by standing beside one.

Masons on Caeldon who carve a bent figure under the keystone of an arch say it is the one who carries; whether the figure comes from tales of the Load-Bearers is not known.