Warlord of the Gravitic Portal

From publisher blurb: After a failed coup attempt, the evil warlord responsible flees into the Martian wilderness with the heroes in hot pursuit. But the hunters swiftly become the hunted as the devastating power of the Gravitic Portal is revealed, an Ancient Martian device that has the potential to destroy not just Mars, but Earth too! Warlord of the Gravitic Portal is a 20-page black and white PDF featuring a Rocket Age adventure for 2 to 6 players.