Matlock is the county town of Derbyshire — its administrative centre, seat of the county council, and the address to which official business is directed. It sits in the Derwent Valley where the River Derwent has cut a limestone gorge through the White Peak plateau, flanked to the east by the sheer face of High Tor and overlooked from the ridge by the ruins of Riber Castle. In geographical terms it occupies the hinge point between the open moorland of the north and the lowlands of the south — not quite in the hills, not quite out of them.
Directly to the south, the gorge continues to Matlock Bath, a different kind of town entirely: a Victorian spa resort that drew the wealthy to its thermal spring waters and still draws visitors to its illuminations, its cable cars to the Heights of Abraham, and its fish-and-chip shops pressed against the river's edge. Matlock proper — which is to say the upper town, the administrative one, the one with the council offices installed in the Victorian pile of the former Smedley's Hydro — has always had a more businesslike character. It is where things are registered, processed, and filed. It is the town that deals with the county on paper.
Within the Book of Thoth Saga, Matlock functions in this same register — as infrastructure rather than spectacle, as the machinery behind the visible landscape of Hope's End and the Peak District. Whatever official records pertain to Robert Knight's situation — school enrolment, medical registration, the address at which he is legally resident — run through Matlock in some form. And in the winter following his first major manifestation, the town becomes something else: one of five points in a pattern that is tightening around the county with quiet, methodical intent.