Canada 1917 WWI Military Soldier KILLED IN ACTION Admiral Cover to France

Cover franked with three 1c Admiral War Tax, postmarked Upper Stewiacke (AP 6), to a soldier in France, Field Post Office 183 c.d.s. on reverse (5th Canadian Infantry Brigade, 25th Battalion), struck on front UNDELIVERABLE FOR REASON STATED / RETURN TO SENDER and CANADIAN CONTINGENTS RECORD OFFICE POSTAL REC'D (JUL 4), manuscript KILLED IN ACTION on front, some toning to one stamp, a tragic piece of First World War history.