Still recovering from the brutal murder of her husband, financial consultant Bay Tanner finds herself once again enmeshed in crime when shirttail cousin Mercer Mary Prescott drops disastrously into her life.

Jailed for vagrancy, Mercer is sprung by Bay's father, a wheelchair-bound retired judge. Vulnerable one moment, sly and secretive the next, the scruffy young woman seems obsessed with the history of Bay's aristocratic family. Her prying is interrupted, however, when she is hauled from the Judge's antebellum mansion and charged with trespassing at a nearby nuclear facility.

Bay's relief at the departure of her meddlesome cousin proves short-lived as a procession of dangerous characters come gunning for Mercer, now on the run after escaping from her police escort. When Bay's housekeeper is viciously attacked, she launches her own search, enlisting the aid of computer genius Erik Whiteside and her brother-in-law, sheriff's deputy Red Tanner. As the body count rises and Bay finds herself confronted by a group of ruthless anti-nuke fanatics, only Mercer can explain the connection between the terrors of the present and the long-buried secrets of Perdition House.

Like the two previous Bay Tanner novels, Perdition House is an original, complex mystery filled with the breathtaking beauty of the South Carolina Lowcountry and the unique traditions of a Southern aristocracy still clinging tenaciously to its past.