However, there are more pressing matters; humanity faces a serious bottleneck, with the Earth reeling from the effects of anthropogenic climate change and resource depletion; automobile production has all but ceased, except for hydrogen-based mass transit, and air travel is limited to the very rich.

Due to climate change, the oceans have become dead zones, with rising sea levels and severe weather displacing millions.

While working in Siberia, Michael's son Tom is injured by an explosion of methane gas from previously frozen hydrates, suddenly released from the now-melting tundra.

With the help of an artificial sentience named Gea, he discovers that a potential release of all such frozen greenhouse gasses could destabilise the environment enough to make the Earth untenable for human habitation, in a repeat of the Permian extinction.

Tom, John, and the elderly George (a principal character of Coalescent) reunite, and a maverick geoengineering company funds the project.

As part of a government program called the "Redemption", Alia is obligated to witness the life of Michael Poole, from start to finish.

Lastly, if that is seen as too great a task, the Transcendence is prepared to reach back in time and stop humans from ever existing, thereby "erasing" the suffering that they intend to redeem.