Little Murders by Agatha Christie: Le crime de Noël

SINOSSI

A Father Christmas is murdered one night at a Christmas market. Six year old Louison witnesses the murder while running away from the orphanage where she lives with her brother, and her life is now in danger. Despite his aversion to children, Commissaire Laurence becomes their bodyguard, and his secretary Marlène delights at playing mother. The solution to the mystery appears to center around Louison's strange orphanage, an institution well known to journalist Alice Avril, who spent her childhood there.