A handbook issued by the Central Office of Information on spies with references to some well known names, a few case histories and the issues for employees in the Civil Service and government departments regarding espionage and how to identify acts as well as avoid being a target. 

Their Trade is Treachery, For official use only. Prepared for Her Majesty’s Government by Central Office of Information. Printed in England for H.M Stationery Office by C. Nicholls & Company Ltd, The Philips Park Press, Manchester. Original document not a reproduction / copy.

Cover is in very good condition with minor wear.  Internal pages are clean and unmarked.