Selling exotic firearms under her alias, the ‘Brass Queen,’ has kept her baronial estate’s coffers full. But when US spy, Trusdale, saves her from assassins, she’s pulled into a search for a scientist with an invisibility serum. As royal foes create an invisible army to start a global war, Constance and Trusdale must learn to trust each other. If they don’t, the world they know will literally disappear before their eyes.