The Thirty-nine Steps by John Buchan

The Thirty-nine Steps, written in 1914, is the first of five thriller/espionage novels in the Richard Hannay series by John Buchan. Barely a hundred pages long, Buchan's story begins with his thirty-seven year old hero returning to England after a long period in Africa. Disappointed and fed up after only a month of his new life, he believed himself to be 'the best bored man in the United Kingdom.'

Less than twenty-four hours later he becomes caught up in an international plot intended to incite a world war.
Hannay's adventures began when Scudder, a strange, nervous little man living in a nearby flat came to him with a wild tale of an anarchist conspiracy.  Hannay believed the man was genuine, if not a little mad, and gave him shelter as Scudder was in mortal fear of his life. Three days later, Hannay returned to his flat after a business meeting to find his guest lying sprawled on his back with a long knife through his heart pinning him to the floor.
Any doubt of the veracity of Scudder's tale had gone and Hannay found himself placed in a position where both the conspirators and the police were after him.
Assisted by the discovery of Scudder's pocket book which contained some details of the plot, Hannay embarked on his escape initially masquerading as a milkman and thereafter in various other disguises. The chase begins and Hannay is hunted throughout the Scottish countryside (beautifully described by Buchan) and in a series of highly improbable encounters and Providences, he eventually gains the help of Sir Walter Bullivant, a senior official in the British Foreign Office.

Suddenly I remembered a thing I once heard in Rhodesia from old Peter Pienaar...
He was the best scout I ever knew...
Peter once discussed with me the question of disguises, and he had a theory which struck me at the time. He said, barring absolute certainties like fingerprints, mere physical traits were very little use for identification if the fugitive really knew his business...
If a man could get into perfectly different surroundings from those in which he had been first observed, and - this is the important part - really play up to these surroundings and behave as if he had never been out of them, he would puzzle the cleverest detectives on earth.


The Thirty-nine Steps is a quickly paced story, and although it lacks the depth and level of mystery of some of Buchan's later novels, it is a great introduction to the espionage genre and his novels in general, especially for a younger reader.
Although it has the peculiarities and prejudices of its time it lacks the sordid material that often inhabits other more contemporary books of this nature. Most of my children read this book around the age of 13 and thoroughly enjoyed it and have read many of his other novels.
There are some of his novels that are better left until later (Witch Wood, for example) but the remaining four Richard Hannay books would be enjoyed by the 14 to 16 year old age group.

These are:

Greenmantle (1916)
Mr. Standfast (1919) - my favourite; contains allusions to The Pilgrim's Progress
The Three Hostages (1924)
The Island of Sheep (1936)

The Thirty-nine Steps can be found at Project Gutenberg and a good Kindle version is available here.
Librivox has a well done audio narrated by Adrian Praetzellis.