Published in Jumbo Comics #21, Oct 1940 - 8 pages
Into a peaceful north-European coastal town ZX-5, wearing a naval uniform, watches a large number of armed men coming from freighters. Spies have sent messages to the forts in the country ordering them to lay down their arms. ZX-5 races to the minesweeper Olav looking for help and that lone vessel is all that stands in the way of the incoming invading navy.