The Snake Pass carries the A57 road across the summit of the Dark Peak between Sheffield to the east and Glossop in Greater Manchester to the west. At its highest point, near the Bleaklow plateau, it reaches approximately 512 metres above sea level — one of the highest classified road crossings in England, and one of the most reliably difficult. Snow arrives early here and stays late. Ice forms on the exposed ridgeline when the valley roads below are merely wet. Wind crosses the open moorland without the interruption of trees or buildings until it meets the road. The Pass closes when conditions require it, which is regularly, and which disrupts the Sheffield-to-Manchester route until it is cleared or reopened. Traffic is then diverted via Woodhead or the Longdendale valley, adding time and distance in ways that the radio traffic update summarises in a single sentence.
The road takes its name from the Snake Inn, a coaching house at the foot of the descent into the Ashop valley. The inn takes its name from the crest of the Cavendish family — the dukes of Devonshire, whose estate at Chatsworth funded the road's construction in the 1820s. The snake, therefore, is heraldic, not topographic; the road is straighter than the name implies. But on the open moorland, in winter, with fog closing the visibility to thirty metres and the snow coming in horizontally off Bleaklow, the topographic interpretation is easier to believe.
Within the Book of Thoth Saga, the Snake Pass is heard rather than seen. A radio traffic update reports delays, and the Pass is named, and this is the entirety of its appearance. It is not nothing. In the context of where the radio is heard and what is happening in the foreground, the detail carries its full weight.