Infinite worlds. Extreme danger. One fearless woman. Passerina Fowler just wants to be a professional fighter. She has struggled for years to make a name for herself. But then her life abruptly changes when she's discovered by a recruiter from SafeTrek Bridging, a company that transports clients to alternate versions of Earth. With nothing to lose, Passerina accepts a job as a bridger, an elite fighter who protects clients on excursions to alternate worlds. However, on her first day she witnesses a horrifying event and realizes bridging can be downright deadly.

Some worlds are better left alone. Infinity Fowler has been fighting all her life. As a kid, she fought to survive. Then, she fought professionally. When humans obtained the technology to bridge to alternate versions of Earth, she saw a chance for a new life. She signed up to become a bridger—an elite survival expert who protects tourists bridging to alternate worlds. Desmond Weaver is making a last-ditch effort to complete his PhD in evolutionary biology. He has booked the excursion of a lifetime, a data-collecting mission to a vastly different version of Earth.

Heart to blood, muscle to bone, tourist flesh above my own. It’s the bridgers’ directive: risk your own life to save tourists bridging to alternate worlds. Bridger Infinity Fowler has no qualms about the directive. Risking death is just what bridgers do. But now the earth is dying. Bridgers have a new directive—save as many humans as possible, even if some must be sacrificed in the process. Sacrificing lives is not what Infinity signed up for. Desmond Weaver, determined to help save the human species, has volunteered to be Infinity’s partner.

A devastated world. A desperate colony. As Earth’s destruction approaches, bridgers Infinity Fowler and Desmond Weaver wrestle with the fact that eight billion people are about to die. While on the road to see Desmond’s mother one last time, they witness chaos like nothing they’ve ever seen. Infinity and Desmond must fight their way back to SafeTrek to fulfill their primary duty—saving the human species. Their next mission: bridge 718 civic leaders to an alternate world.

Earth’s last refugees. A one-way trip. A world of terror. Time is up. Earth is collapsing. Eight billion people and countless other living things will die. Bridgers Infinity Fowler and Desmond Weaver have one last chance to save a handful of refugees. And one last chance to have a life together. Earthquakes and storms threaten to destroy humanity’s last hope—the SafeTrek bridging facility. With the building literally collapsing around them, Infinity, Desmond, and a small group of refugees manage to bridge out. Their destination: an alternate world similar to their own.

Annihilation has a way of following some people. Infinity and Desmond are bridgers, sworn to protect travelers to alternate versions of Earth. But now their own Earth has been destroyed, and they have a new task—protecting a small community of fellow refugees who managed to escape to a world teeming with giant arthropods. Stranded there, they’ve gradually managed to etch out a fulfilling existence. But it seems nothing good can ever last. Infinity and Desmond’s hopes of living out their lives in peace are shattered when their old friend Armando inexplicably bridges to their world.

On the brink of extinction, a final struggle begins. Earth is dead. Infinity and Desmond, the only surviving bridgers, believe they’ve been given one final chance to find peace. Leading a small group of migrants, they bridge to a new world for the last time. Their new home appears to be perfect—pristine islands encircled by sparkling beaches and a coral sea. However, there is one catch—they’re not alone. Infinity, Desmond, and their fellow migrants knew they’d have to share their new home with another sentient species. They were told these other beings would not be a threat.