The novel explores the heavy burden of carrying a shared secret for two decades. Naomi, Cassidy, and Olivia each cope with the guilt and fear in different ways, highlighting how unspoken truths can fester and poison relationships over time. The constant threat of their lie being exposed creates a palpable tension that drives the narrative.

"What Lies in the Woods" delves into the complexities of childhood friendships and how they evolve – or disintegrate – in adulthood. The intense bond formed in the crucible of a shared trauma both holds the women together and threatens to tear them apart as their perceptions of the past diverge. The story examines how childhood loyalties can be tested and twisted by time, trauma, and differing memories.

The girls' creation of the "Goddess Game" serves as a constant reminder of the power of imagination, particularly in childhood. However, the lines between their fantastical game and the harsh reality of the attack become increasingly blurred, raising questions about the reliability of memory and the influence of trauma on perception. The novel explores how childhood fantasies can have lasting and often unsettling consequences in adulthood.