Sam Flood and Miguel Madero saw each other for the first time in a motorway service café to the west of Manchester but neither would ever recall the encounter.

Sam was sitting at a table with a double espresso and a chocolate muffin which was far too sweet but she ate it anyway. She glanced up to see Madero passing with a cappuccino and a cream doughnut. Though he wore no clerical collar, there was something about him – his black clothing, the ascetic thinness of his face – which put her in mind of a Catholic priest, and she looked away. For his part all he registered was an unaccompanied child whose exuberance of red hair could have done with a visit to the barber, but most of his attention was focused on maintaining the delicate relationship between an unreliable left knee and an overfull cup of coffee.

She left five minutes before he did and they spent the next hour only a couple of miles apart in heavy traffic. Then a van blew a tire a hundred yards behind her and spun into a truck. Miraculously no one was seriously hurt, but as Sam’s Focus sped merrily north, Madero and his Mercedes SLK fumed gently in the accident’s tailback.

From having time to spare for his two o’clock appointment in Kendal, he was already half an hour late as he reached the town’s southern approaches.

On the map Kendal looked to be a quiet little market town on the eastern edge of the English Lake District, but there seemed to be some local law requiring all traffic in Cumbria to pass along its main street, which meant it was after three when he drew up before the chambers of Messrs. Tenderley, Gray, Groyne, and Southwell, solicitors.