N or M?

Collins brings the Queen of Crime, Agatha Christie, to English language learners.Agatha Christie is the most widely published author of all time and in any language. Now Collins has adapted her famous detective novels for English language learners. These carefully adapted versions are shorter with the language targeted at upper-intermediate learners (CEF level B2).Each reader includes: A CD with a reading of the adapted storyHelpful notes on charactersCultural and historical notes relevant to the plotA glossary of the more difficult wordsIt is World War II and Britain's best secret agent has been murdered. The murderers are Nazi agents, known only as N and M, and could be anyone. The only clue points towards the sleepy seaside village of Leahampton and its busy guesthouse, Sans Souci.Tommy and Tuppence Beresford, Britain's most unlikely spies, accept the mission to find N and M. No one can be trusted...