Sixteen-year-old Wren MacAvoy works as a coal miner for a domed city where, after 200 years, society is complacent and coal is diminishing until she unwittingly becomes a catalist for a revolution that destroys the dome, which could mean the end of everything.

Wren and her friends are caught in the middle as the battle between factions inside and outside the dome escalates, and it is up to Wren to make both sides see that their only chance of survival is to work together.