Dark Sisters: A Cait Reagan Novel (Boston Preternatural Investigations Unit Book 4)
Boston Preternatural Investigations Unit • Book 4
by Aoibh Wood
Why You'll Love This
When the Light Fae turn out to be the monsters, Cait Reagan's rescue mission to Ireland becomes something far darker than she bargained for.
- Great if you want: urban fantasy with messy relationships, morally complicated fae, and queer leads
- The experience: fast-moving but layered — tension builds through character fractures, not just action
- The writing: Wood juggles a large cast without losing individual voice or emotional stakes
- Skip if: you haven't read the earlier books — continuity runs deep here
About This Book
Boston's most reluctant supernatural investigator is crossing the Atlantic, and the stakes have never been more personal. In Dark Sisters, Cait Reagan races to Ireland to rescue her sister Aoife, only to find that the Light Fae—creatures she once might have trusted—have become something far more dangerous. Add a tangled emotional triangle, an unwilling hostage who may be more important than anyone realizes, and a close ally whose changes are quietly terrifying, and Cait's mission becomes less a rescue and more a reckoning. Wood doesn't let her protagonist off easily: every relationship is tested, every alliance is suspect, and every step toward saving one person risks losing another.
What rewards readers of this fourth installment is Wood's commitment to character density without sacrificing momentum. The prose moves with purpose, balancing mythological texture—Irish folklore rendered with genuine weight—against the grounded procedural energy the series built from the start. Cait's voice remains sharp and emotionally honest, never melodramatic even when the world around her tilts toward chaos. Readers who've followed the series will find payoffs here; newcomers will find enough momentum to pull them forward regardless.
