Living in a small village in Occupied France during the Second World War, the child Marcel and his two older brothers Ren and Pierre are more concerned with their lying games and with their ability to outwit the adults, especially Maman. But strange things happen.
Jewish guests arrive and then disappear.
At the same time their beloved dog Mirabeau is mysteriously lost. German soldiers are seen in their village. Only when an accident occurs are the two youngest let into the great family secret of the war. Now lying is serious business involving both children and adults. Only the good liar will survive the war.