Four miles south of Grey Crag. There, the smooth Macadam turnpike sliced through the dark rock ridge at Culvert Twelve, the winter air was crisp and still.
The road here was twenty-four feet wide, engineered with a three-inch center crown that shed snowmelt into deep, stone-lined drainage gutters on either side.
Upright rock cuttings, thirty feet tall and dressed with clean stonework retaining walls, rose sheer on both flanks. That created a natural mountain choke point.
Beneath the roadway ran Culvert Twelve, a building triumph completed during the late autumn road spreading.
The under-road drain was a ten-foot half-round barrel vault built from dressed granite arch stones, designed to channel the pouring spring runoff of the Whitefall torrent beneath the turnpike without undermining the roadbed.
Giles Croft had personally surveyed the arch, specifying a two-foot concrete saddle over the crown to distribute heavy axle loads evenly into the bedrock abutments.
Because of that solid stonework foundation, the road didn’t flex, rut, or heave under the heaviest four-wheeled baggage wagons.
It was smooth, hard, and fast. Which made it an ideal killing ground for a high-speed vehicle ambush.
