The man known as X-5 Secret Agent was a spy for a U.S. government agency during World War II. In his first appearance he is in the neutral country of San Miguel when he sees the enemy battleship the searaider "Wolf" refueling in the dock. Later in a bar he overhears a conversation from the Baroness Verber about sinking the American freighter the Arkian when it comes. After a confrontation with the baroness and her associate, he goes to warn the captain of the Arkian but arrives too late for the ship to leave the harbor completely and they are shelled by the enemy sea raider.