The Charlemagne Pursuit (Cotton Malone Series #4)

As a child, former Justice Department agent Cotton Malone was told his father died in a submarine disaster in the North Atlantic, but now he wants the full story and asks his ex-boss, Stephanie Nelle, to secure the military files. What he learns stuns him: His father’s sub was a secret nuclear vessel lost on a highly classified mission beneath the ice shelves of Antarctica.

But Malone isn’t the only one after the truth.

Twin sisters Dorothea Lindauer and Christl Falk are fighting for the fortune their mother has promised to whichever of them discovers what really became of their father–who died on the same submarine that Malone’s father captained.

The sisters know something Malone doesn’t: Inspired by strange clues discovered in Charlemagne’s tomb, the Nazis explored Antarctica before the Americans, as long ago as 1938. Now Malone discovers that cryptic journals penned in “the language of heaven,” inscrutable...