Krivitsky soon returned to North America, landing in Canada. Always in trouble with the U.S. Immigration and Naturalization Service, Krivitsky was not able to return there until November 1940. Krivitsky retained Louis Waldman to represent him on legal matters. (Waldman was a long-time friend of Isaac Don Levine.) Meanwhile, the assassination of Trotsky in Mexico on August 21, 1940, convinced him that he was now at the top of the NKVD hit list. His last two months in New York were filled with plans to settle in Virginia and to write but also with doubts and dread.