Julian Reeve, a college student facing personal uncertainty, boards a flight home. Midway through the journey, a catastrophic engine failure forces Julian and three other passengers to parachute into the Atlantic Ocean, crash-landing on a remote island. Initially focused on survival, they scavenge supplies and attempt to construct shelter.
Shortly after their arrival, the group is approached by an armed team led by a young woman named Emma Blake. Using advanced technology, Emma’s group opens a portal and transports Julian and his companions to a fortified enclave. There, the survivors are placed under quarantine, and Julian uncovers information about their situation through a journal written by an early survivor. The journal reveals that a failed time-travel experiment in 2098 fractured Earth into isolated islands, each housing fragmented prehistoric eras and ecosystems.
Upon release from quarantine, Julian struggles to adapt to enclave life. With limited skills and physical conditioning, he must train in combat, survival techniques, and manual labor in order to contribute to the community. He takes up work in the enclave's forge and begins daily sword training under Emma’s guidance, marking the beginning of his transformation from an inexperienced outsider to a capable resident of the enclave.