Wonderful war stories about Isidor Katanic, officer who spent his working life as a calligrapher writing to various documents. Resignation living at home, living with rampant wife and her son from a previous marriage, sloth. Very soon retire and go to the river. On the bank of the Sava river meets an old friend, a former captain in love with the river. Accepting new way of life, isidor becomes a different man. But it comes terrifying wartime.Yugoslavia was occupied, the terror begins. Isidor is witnessed changes and in him growing need to resist the atrocities of the invaders. He refuses to flee with his family from Belgrade, it becomes illegal brave, little hero of invisible front.