Is Carl Andersen innocent of murder, or a very good liar?

Detective Chief Inspector Maigret has been interrogating the enigmatic Danish aristocrat for seventeen hours. A diamond merchant was found dead, shot at point-blank range, in the garage of Andersen’s mansion, yet he will not confess to the crime. To get to the truth, Maigret must delve into the secrets of Three Widows Crossroads, the isolated neighbourhood where he lives with his mysterious, reclusive sister Else – and where, it seems, everyone has something to hide.