A long-dead genius. A hidden invention that could save-or doom-humanity. Can Leif find it before it falls into the wrong hands?

The Martian Girl is a myth, some people say, created in the dark years after an apocalyptic global war. Perhaps she was a genius in mathematics and the greatest theoretical physicist since Einstein and Hawking. She may have made a mathematical breakthrough or a powerful weapon. No one knows for sure.

In AD 2726, Leif Grettison, former army ranger and exoplanetary scout, returns from the stars a weary man. Four and a half centuries have passed since he was last on Earth. Now, statues honor him, and history books extol the almost-accurate legends of Lucky Leif. But all he really wants is a small cottage on a hill with a good view and no neighbors. (Good luck with that, Leif!)

Leif knows nothing about the Martian Girl. But when he agrees to a simple request, his path leads to a relationship he never expected, two teens nobody wants, and a scheme to revive the Martian Girl's former home, a dead city on Mars. Suddenly, discovering what the Martian Girl did is the center of Leif's life.

Bringing a city on Mars back to life is hard enough, but some of the team are agents of competing powers, each determined to find what the Martian Girl created. They will resort to anything, even murder, to possess it.

If there is a weapon and Leif cannot secure it, his friends will be in danger, the shaky peace on Earth will collapse, and the world may plunge into devastating wars.

Can a legend still gripped by his past save our future? Or will the Martian Girl's invention push humanity over the brink?