It seems like a dream gig when Daphne gets the job offer—live in Montreal's Underground City for a full year and blog about the experience. The flip side of the city has all the creature comforts. The year will fly by. Except there's a catch. To collect her whopping bonus for sticking it out till day 365, Daphne must agree never to set so much as a toe outside the territory of the Underground City, submitting to an ankle monitor to keep her honest. Even if the conditions are hardcore, she doesn't have much choice. Out of work, and sole provider for a grandmother whose bank account is on life support, Daphne signs on the dotted line. And that's when her life goes into freefall.

Inspired by Daphne, her grandmother comes up with an underground plan of her own, sheltering a family of illegal refugees in her basement. Daphne's initial fury at her grandmother's risky move does an about-face once she meets Chantal, a young runaway holed up in the Underground City, fleeing a threat she refuses to disclose. When Chantal shows up on Daphne's doorstep desperate for protection, Daphne must decide if she's prepared to lay her underground future on the line to rescue a group of virtual strangers from discovery and ruin.