Wrest Park’s leonine stone dog awaits his jackdaw tormentor as the fog descends. Photograph: Sarah Niemann

A strange, pale coloured beast, part dog part lion, was seated on the balustrade of a Victorian terrace. Out of the fog came a jackdaw which landed on its stone head. The bird fidgeted restlessly, clawing the animal’s face with its talons, then took off again.

The jackdaw called from the milky stillness and its cry came back as an echo of an echo of an echo.

I turned to the wall of the mansion house. At one level the edifice might have been described as composed of rectangular blocks of Bath stone. At a deeper, closer level, the burnt gold surface revealed itself for what it was: a Jurassic seabed, diced and dragged from ground to the west and mounted here as a vertical cliff.

The surface was textured like the inside of a Malteser, a cratered landscape. Rills of crystalline threads told of prehistoric chemical impurities, trapped and transformed, while fossilised life from a hundred million years ago was all too apparent. Among the unidentifiable shards floating in the limestone was the corrugated rim of a cockleshell protruding from the rock face.

Though this stone was the perfect preserver of death, it appeared hostile to life. Grey foundations of a different material at the base of the wall hosted tiny green and orange lichens, and accretions of soil had left an anchor there for thin strips of moss, fruiting little stalks like unlit birthday candles. By comparison, the limestone seemed a pitted, pitiless, desert.

But then I spied a spider, black with a crimson patterned abdomen, so small it could almost sit within a single crater. On two legs pearly water droplets hung from its knees, which in spider dimensions were the size of footballs. These appendages were no hindrance, it appeared. The spider began to groom itself, then crawled away.

I returned to the balustrade. A stonemason had chiselled plants and flower heads on to the columns. At the very end of the terrace I found a carved spiral, glorious in its imperfection. The very act of cutting had exploded a geode, a crystal ball – an unavoidable canker at its heart.

Twitter: @DerekNiemann