Vine And Vice. Undertow Sins, #30

Some men build walls to keep the world out. He carved a cave and kept the world inside it. Special Agent Jessamine Thorne has one mission: infiltrate the isolated Napa Valley estate of Ledger Cross, a vintner suspected of running a massive, unlicensed wine distribution network that bypasses federal law. Her cover is simple-a freelance wine writer profiling independent estates. Her goal is absolute-document the operation, locate the distribution tunnels, and dismantle the network that has evaded federal authorities for years.
But Ledger Cross is not a simple target. He is a man carved from his own land, possessing a quiet, dangerous intensity that challenges Jessamine's professional detachment from the moment she steps onto his property. When a ferocious wildfire erupts, turning the valley into an inferno, the access roads are destroyed, leaving Jessamine trapped in the one place she never intended to be: inside Ledger's reinforced underground cave system.
Now, Jessamine and Ledger are bound by forced proximity in a claustrophobic world of oak barrels, volcanic stone, and impenetrable dark. As the fire consumes the world above, a high-stakes psychological game begins. Ledger knows exactly who she is, and he's been waiting for her to reveal her true intentions. In the heat and shadow of the caves, Jessamine uncovers a devastating connection between their families' pasts-one that proves the line between investigator and target is as thin as the smoke filling the air.
Surrounded by secrets, Jessamine must decide if the man who controls the dark is her greatest enemy, or the only one who can help her survive the fire she helped ignite.