[1] Axis takes place on the new planet introduced at the end of Spin, a world the Hypotheticals engineered to support human life and connected to Earth by way of the Arch that towers hundreds of miles over the Indian Ocean.

Humans are colonizing this new world — and, predictably, fiercely exploiting its resources, chiefly large deposits of oil in the western deserts of the continent of Equatoria.

Lise Adams is a young woman attempting to uncover the mystery of her father's disappearance ten years earlier.

A quasi-religious group of "Fourths" from Earth, led by Dr. Avram Dvali, lives in the desert seeded by falling dust.

The Fourth-hunting "Department of Genomic Security" is searching for this group or for a visiting Martian Fourth who disapproves of Isaac's creation.