A search for a son

This is an account of a father's attempts to discover what has happened to his son, who disappeared in the Darien Gap Jungle in Panama, in Central America.
Just how do you go about finding out what has happened to someone six thousand miles away in a Spanish-speaking country?
At the start the father did not know for definite where how his son had disappeared, if he had had a companion or who that companion was, or if he had had a guide.
The significant thing is that the search became a family affair (without divorce!), but then other people became involved - some complete strangers very generous and helpful, a genuine crook, and two largely incompetent detective agencies.
After 9 months, it was resolved, free of any ransom demand, probably by direct contact with the guerrilla group, FARC, itself.
When the two adventurers were released, the parents, Brian and Anne Winder, heard of ransom demands of $2.000,000 each which never reached them, and many situations where the two adventurers could easily have died, and their fate never be known.
Brian Winder is a family man with three grown-up sons and a long-suffering wife who is a French teacher. He was born and educated with degrees in Classics and Philosophy with the Jesuits in Ireland.
In his 20s he travelled in North Africa and most countries in Europe, and most interestingly in Russia when it opened its borders. He taught in a secondary school in Zambia and also worked in the copper mines in Zambia for 11 years and in London, after he specialised in computers and as an accountant.
After retirement, he devoted himself full-time over 25 years to volunteering with many roles in charities serving the homeless and addicts. His favourite hobby is country dancing.