The route follows the A83 to the head of West Loch Tarbert, where it turns left about 2 km before Tarbert onto a short unclassified road, before turning left onto the B8024, which it follows around the west coast of Kintyre, crossing again to the east coast to meet the A83 about 5 km south of Ardrishaig, where it leaves the A83.
However for a time the main suspect was Marion’s husband, William, who had been on a fishing holiday in Ardrishaig, but was suspected of driving around 90 miles through the night, faking a break-in to his own house, murdering his family, and driving back.