Caesar, an undercover operative, enters Carmichael with the briefest of orders from his boss and a countdown on his phone. What will happen when the clock strikes zero? Deputy Amelia Miller is dispatched from a nearby city, and a series of events keeps her around much longer than she'd expected. In the middle of the night, something shifts, and the whole town disappears off the face of the Earth. Who caused the shift, and what lies beyond the veil of their settlement?

Caesar and Anders find themselves on a dangerous quest to save the only man who can bring them home. But Logan Rutherford is sought by others, and whoever reaches him first will harness the power of Arcadia. Amelia is quickly appointed Chief, yet the role comes with unforeseeable dangers. She soon realizes the town holds dark secrets connected to the Shift, but some secrets are best kept buried.

Caesar and Amelia must part ways on crucial tasks to relocate their people from the incoming war. Milton is days away from reaching Lost Town, but is it enough time to prepare when he's been training for this his whole life? Harrison gets a second chance at redemption as he ventures to Earth to save the inhabitants of Arcadia. His optimism fractures when a rogue team of assassins is recruited to thwart his mission. And what other secrets lay beyond Arcadia?

Most of Carmichael's population made it home, but not everyone wants to return. Both parties must start again, and life as they knew it has changed forever. Caesar and Amelia are recruited by Harrison to bridge the gap between Arcadia and Earth, while Anders is hired to rescue John and Lillian from whatever distant planet they now occupy. The journey begins at Wayward, the renamed town that Milton had once tyrannized. Milton may be a distant threat, but Duffy, wounded and outraged, still lurks in the shadows.

Lost Town is being rebuilt in the wake of tragedy. With no connection to Earth for three months, Caesar has the chance to regroup and determine the threat level from Lithos. John can't shake the sensation that the worst is yet to come, and it's confirmed when Anders and Haley leave to investigate a potential second alien tower on Arcadia. While Harrison takes a step back, Amelia must keep the peace between the rogue agents who are putting their mission in danger. Meanwhile, on Earth, Summer is contacted by a mysterious stranger who predicts a looming invasion.

The Shift is closed between Earth and Arcadia. The residents of Lost Town acclimate to their new reality. They are forever stuck on another planet, with only each other to rely on. Amelia, anxious to see more of their home, travels with Milton's old map-filled journal, discovering an ancient civilization. John is eager to start a new life, until tragedy strikes at the heart of Lost Town. Restarting from scratch isn't ideal, but the locals will do anything to succeed.