Birnam Wood is on the move... A landslide has closed the Korowai Pass on New Zealand's South Island, cutting off the town of Thorndike and leaving a sizable farm abandoned. The disaster has created an opportunity for Birnam Wood, an unregulated, sometimes-criminal, sometimes-philanthropic guerrilla gardening collective that plants crops wherever no one will notice. For years, the group has struggled to break even. Then Mira, Birnam Wood's founder, stumbles on an answer: occupying the farm at Thorndike would mean a shot at solvency at last. But Mira is not the only one interested in Thorndike. The enigmatic American billionaire Robert Lemoine has snatched it up to build his end-times bunker, or so he tells Mira when he catches her on the property. Intrigued by Mira and Birnam Wood, he makes them an offer that would set them up for the long term. But can they trust him? And, as their ideals and ideologies are tested, can they trust one another?