Wartime espionage

How did Boudewyn gets interested to become a 'spy'? 

Boudewyn worked with a Eurasian food contractor who supplied Indian army camps in Singapore. While making deliveries, he met a prisoner of war from the British Indian Army and learned of the ill- treatment by Subhas Chandra Base's Japanese- backed Indian National Army (INA) of those who refused to join INA. Boudewyn admired the bravery of those who remained loyal and wanted to avenge those who had suffered for it.  

How did Boudewyn knew about the documents and where did he kept it? 


Boudewyn's new friend told him that the documentary proof would be obtained and planned to gather those evidence. Each day, his contacts would purchase vegetables and later claim some were rotten and return them with the documents stolen from the military's office. Boudwyn kept the papers of evidence where he left the camp and the bicycle carrier where it was never searched. He did this until 1944 when he had all the relevant documents and stored them in an oil drum burried beneath a friend's tennis court in Chancery Lane. However, the Japanese converted the tennis court into a vegetable garden. Therefore, after the war, this made locating the drum difficult but was later discovered that while he had taken care to bury it four feet deep, it was only now one foot below the surface.