A file of correspondence and memoranda concerning the investigation of the Corby case, in which the defection to Canada of Soviet embassy worker Igor Gouzenko revealed the existence of a Soviet espionage network in Canada. The documents in this file discuss the legal procedures for the arrest of the network’s agents; the scope of a report on the network by a Canadian Royal Commission; the presentation of a copy of the report to the Soviet embassy; the need to reply to a Soviet statement downplaying the significance of the arrests; a list of intelligence items collected by the network, including information about the capabilities of the Canadian armed forces; descriptions of some of the network’s agents; minutes for a press conference concerning the case; and a memorandum on the organisation and structure of the Soviet intelligence services controlling the Canadian network.