They assessed the situation. Patches of the truth showed through the badly covered exterior surfacing. However, the object stubbornly resisted any attempt to uncover it completely. Standing about chest height, and shaped like a mini stonehendge, the surface was covered in strange finishes, each of which showed a different age. It was impossible to date the object with any accuracy. It's true nature was a mystery. Over the years, multiple efforts to disguise the surface had resulted in drastic measures being required. They had to know what they were truly looking at.
They decided after about four hours work, that they had done enough. They had uncovered the centre of the object with amazing ease, although this had set them wondering about the deeper mysteries that lay in the dark tunnel above them, linking the object to the top of the structure in which it was housed. Cursory examination with a torch had reavealed little. The surface of the object itself had been partially revealed.
They began to clean down the dust caused by grinding carefully at it's multi-layered surface. The dust was milimetres thick, showing all the hard work that they had done. Sweat poured from their bodies, causing the dust in the air to stick to their skin. When they ground their teeth together, they could feel the powder coating them. They were both short of breath. The shorter of the two quietly pondered on the possible after effects of this dust on his lungs and eyes.
The plastic sheeting covering the expensive electrical equipment was eventually removed. Several screens on desks showed layers of the dust. They growled about having to clean every object individually, and set to with wet rags.
The nature of the object was becoming clear after hours of working. Dark grey slate gleamed in the evening late. The cleaning finally finished, and the dust finally showered off them, they looked at the fruits of their labour.
"The fireplace is going to look stunning when we've finished sanding it down to the slate"