In the midst of this upheaval, a charming stranger arrives in town. The newcomer, Red McKenna, quickly befriends fifteen-year-old Sean Flannery, and Sean's sister, Kitty, falls in love with him. But when raids by the Mollies are ambushed by the Coal and Iron Police, Red is suspected of being a spy for the mine owners. The violence escalates, and the Flannery family is left to deal with the consequences of one of the first truly tragic labor conflicts in America.

Intended for middle school readers, ages 11-14, Rebels in the Shadows offers a historically accurate version of a tumultuous time in the Pennsylvania coal mines based on actual documents of the period. Rebels in the Shadows also tells the story of a young man dealing with the demands of adulthood, a father forced to change his beliefs, a mother coping with grief, a young woman discovering and losing love, and a stranger who must choose between duty and morality. Unlike many of the accounts of the period, Reilly has tried to depict opposing sides fairly, and the book offers another look at the plight of the Irish immigrant in America. As with the other Golden Triangle Books, Rebels in the Shadows contains a foreword and an afterword on the historical themes and personalities in the novel.