What if humans discovered the secret to prolonged life? Francis Saxover and Diana Brackley, two biochemists investigating a rare lichen, separately discover it has a remarkable property: it slows the aging process almost to a halt. Francis, realizing the implications for the world of an ever-youthful, wealthy elite, decides to give the lichen to his children, prolonging their lives while keeping his discovery a secret. But the younger and more daring Diana sees an opportunity to overturn the male status quo and free women from the career vs. children binary. As each scientist wrestles with the implications of their discovery, Francis's decision to treat his children backfires—and it becomes clear that there are others who will stop at nothing to possess the secret to prolonged life. When Diana vanishes without a trace, Francis decides that he must find her: to apologize, to help her on her mission, and possibly protect her. But will he find her first?