In 5th-century pagan-dominated Ireland, Brigid is born a slave to her own father and is separated from her mother. Desperately seeking love and acceptance, Brigid becomes a believer in Christ.

Aine, a young woman unwillingly pledged to marry, believes the book is a talisman with the power to change her circumstances. When she steals it from her betrothed’s clan, desperate to use it to help her mother’s impoverished people, events tumble out of control. She seeks help from Brigid, the woman who rescued her long ago, but doing so puts an entire monastery at risk as the king deploys his army to get the book back.

Having escaped a violent childhood, Enya is safe living with her husband’s powerful clan. When her long-awaited son is born, she must fulfill a vow made in desperation—the boy is dedicated to God, and goes to live with the local priest. Still, she clings to the hope that the church’s influence will eradicate any trace of her bloodline’s temperament. The monks rename him Columcille, which means "dove of the church".