Illusion of mirrors - Agatha Christie

A man gets shot in a juvenile corrections home - but someone else dies... Miss Marple senses danger when she visits a friend who lives in a Victorian mansion which doubles as a rehab center for offenders. Her fears are confirmed when a young man puts a gun on official Louis Serrocold. not get hurt. But the mysterious visitor, Mr. Gillibrandsen, is less fortunate - he is shot dead simultaneously in another part of the building. pure coincidence? Thinking so, Miss Marple vows to find out the real reason for Mr. Gillibrandsen's visit