In September 2013 Tony Collins took advantage of a long-overdue sabbatical to walk the 490 miles of the Camino, from the French border to Santiago de Compostela in northern Spain.

For decades he had helped to provide the evangelical churches of the world with reading material.

Now he was deliberately stepping out of his comfort zone: a pilgrimage, carrying his pack, through a land whose language he did not speak, into a religious culture far removed from his own, in search of sources of reverence.

He would not walk alone: the Way has many adherents, well over 200,000 completing their Camino during that year. He had expected the Way to be arduous, and so it proved. But he had not expected so bracing an internal journey, his battered soul laid down for examination, past errors offered up for scrutiny. Nor had he expected such moments of intense spiritual encounter; nor so many precious friendships. He discovered, above all, as have many before him, that the Road leaves an indelible mark.