Isabel had died in 1995 and his search quickly established that she had been born in Argentina and that her father was John Campbell, a rancher. However, three John Campbell's emerged as potential fathers for Isabel and in the process the remarkable histories of these three families were uncovered.
From Prussia and the lowlands of Scotland to the pampas of Argentina and the trenches of the Somme, their stories unfolded, as the attempt to identify the father of the illegitimate Isabel continued.
In a show of patriotism each of the John Campbells or their children returned from Argentina to fight for the British in both World Wars, and documents unearthed told of families being torn apart by war and of the inevitable death and suffering of those involved in conflict.
Seeking John Campbell follows the three families, from the early Scottish migrants to Argentina in 1825 to the end of World War II, as John seeks to identify Isabel's father and discover any living heirs.