Mr. Nice(2011)

Howard Marks was a young Welshman studying at Oxford when he discovered there was something unusual about his dorm room -- it had a secret passageway that led to a storage space used by one of the school's top marijuana dealers. Marks and the dealer struck up a friendship as he became an enthusiastic customer, and a few years later, when plans to bring a large cache of hashish into England via Germany went haywire, Marks stepped in to help. This was his beginning of his career as a marijuana dealer with access to high-level circles in society and politics.