In this provocative work of speculative fiction, two sisters navigate the complex moral terrain of reproductive ethics, individual freedoms, and society’s duty to a future facing imminent extinction.

Charlie Tannehill and her twin sister, Maggie, are just eight years old when an unfortunate scientific discovery upends their world—and the world order. The revelation? Extinction, encoded in every creature’s DNA. The expiration date for humans? Only four generations away.

A decade later, unsure of what tomorrow holds, Charlie and Maggie enroll as counselors in a government-run human-husbandry program. By offering cash rewards for reproduction, they hope to forestall humanity’s decline and discover a genetic mutation that might defeat it. While Charlie struggles with the ethical implications of the work, Maggie makes unspeakable sacrifices to improve her odds of success—but such unchecked ambition could come at a greater cost than even she realizes.

Torn between her own morality, her love for her sister, and the pressures of a vanishing civilization, Charlie must search deep within to decide what she’s willing to sacrifice—for herself, for Maggie, and for society—to salvage hope for the whole of humankind.