The Prisoner in the Castle by Susan Elia MacNeal

The Prisoner in the Castle is the latest in Susan Elia MacNeal’s World War II mystery series featuring Maggie Hope, an American-born mathematician and cryptographer, once a secretary to Winston Churchill, and now a spy working for the top secret organization Special Operations Executive (SOE).  Maggie has been imprisoned on an island off the west coast of Scotland because she knows the plans for the Allied invasion of Normandy and she refused to cooperate with a high-ranking SOE officer who was knowingly sending agents to their deaths.  She and her fellow inmates, also former agents who know too much, are confined to a prison camp in a creepy castle on the island.  They are completely cut off from the outside world, except for one radio that can only be used in emergencies.  Their families and friends all believe they’ve been sent abroad on top secret missions.

Then the prisoners start being killed off one by one.  Maggie knows the killer must be one of them, unless rumors are true that the castle’s former owner is still alive.  He was a cruel and vicious man who supposedly killed his wife and their dinner guests before shooting himself.  But Maggie, unlike some of her fellow prisoners, does not believe the rumors.  She must discover which of the prisoners is killing the others, before she becomes the next victim.  All of them have been trained to kill, but no one seems to have a motive.  At first she suspects Camilla, a new prisoner, because the murders began just after she arrived.  But when Camilla turns up dead, Maggie realizes she was wrong.  Could one of the prisoners be a Nazi spy?  Meanwhile, Detective Chief Inspector Durgin, who had worked with Maggie to catch a serial killer in an earlier book in the series, needs Maggie to testify in the man’s trial, or the killer could go free.  But he has no idea where she is, and the head of SOE will not tell him.  Will Durgin and Maggie’s other friends in London be able to rescue her from the island?

The Prisoner in the Castle is very suspenseful, with many twists and turns.  The characters are well developed, and you come to care about each of the prisoners, and feel bad when they are killed off.  It is an unusual entry in the series, though, because it is a locked-room mystery, very much in the tradition of Agatha Christie.  In fact, there are references to Christie throughout the book.  Most of the other books in the series are spy stories.  But, as always, when you finish reading, you want to know where Maggie’s next adventure will take her.  I highly recommend The Prisoner in the Castle for fans of World War II stories and for fans of Agatha Christie.  It is not necessary to begin the series with the first book, Mr. Churchill’s Secretary.  As a matter of fact, I began it with one of the later volumes and then went back to catch up with the earlier ones.   But it helps to read the series in order and follow the character development of Maggie and her friends.

The Prisoner in the Castle is available from the Hatcher Graduate Library and the Browsing Collection of the Shapiro Undergraduate Library.