In 2017, I read Gin Phillips' novel, FIERCE KINGDOM, which was about a woman and her child trying to survive in a zoo during an active shooter situation. I primarily listened to the audiobook while I was training for a long-distance race. Maybe the fact that I was doing my runs in the predawn hours by myself on the edge of town escalated the tension, but it's certain that Phillips' unique premise and suspenseful writing amped up my heart rate even more than it would have been otherwise.

When I learned that RUBY FALLS is set almost entirely underground, I knew I was in for more adrenaline-fueled reading this time around as I am extremely claustrophobic. Despite sharing that page-turning momentum, it is indeed a very different novel from FIERCE KINGDOM. For one thing, it's a mystery set during the Great Depression. And although the specific premise is not based in historical fact, the setting is very much a real place: a 63-foot waterfall located inside a cave near Chattanooga, Tennessee.

"Whether readers listen to RUBY FALLS in the dark or read it with all the lights on, they'll want to carve out some time to explore this rewarding historical mystery."

The book opens with a lightly fictionalized account of the waterfall's accidental discovery in 1928 during an excavation by Leo Lambert, who named the falls after his wife. In Phillips' telling, Ruby's good friend, Ada Smith, accompanies a small group on the first guided visit to see the falls. She's fascinated not only by the falls themselves but by the wonders of underground exploration, a hobby she pursues more frequently after the death of her husband.

Leo's dreams of striking it rich by turning the falls into a tourist attraction fall on hard times. It's not easy to launch a major business venture during a global economic depression. So in 1931, he hatches a new plan for a much-needed boost in buzz. He hires a famous mind reader, Professor Jeremiah Hagathorn, to participate in a publicity stunt. Two neutral participants (a local businessman and a cave guide) will hide a ladies' hat pin somewhere in the cave. Then, the next day, the mystic will use his psychic powers to find it somewhere in the extensive cave system surrounding the falls. Joining Hagathorn, along with the guide and the businessman, will be Hagathorn's wife and his manager. Just to ensure the event captures the headlines, Lambert has enlisted a Chicago newspaperman to accompany the group and report on the story.

Unknown to anyone else, however, two additional spelunkers will be tagging along, just out of sight: Ada and a man named Quinton, who accidentally discovered Ada’s pastime. They've agreed to keep their presence a secret and just ensure the group's safety. But when one member of the party turns up dead, they have no choice but to reveal themselves. And then the lanterns start to run out of fuel.

Set largely over the course of a single day and almost entirely within the increasingly oppressive and dangerous cave system, RUBY FALLS is a propulsive read. Ada is the central character, but Phillips offers insights into almost everyone else's backstories and motivations…and reveals the many secrets and lies they carry. This isn't just an exciting mystery, though. It also sheds light (so to speak) on the position of women at this time in history, as well as Ada's mixture of regret and excitement at being childless and able to pursue new kinds of passions.

Whether readers listen to RUBY FALLS in the dark or read it with all the lights on, they'll want to carve out some time to explore this rewarding historical mystery.