Each Halloween, the spectral wails of Phoebe, the upstairs ghost, shatter the tranquility of Minerva's life. The haunting begins weeks before the holiday and continues until All Saint's Day, leaving her desperate for respite. Minerva has reached her breaking point.

Her devoted partner, Detective Lance Destry of the Guthrie, Oklahoma Police Department, and Minerva’s newly adopted daughter, Lark, with her partner, Eddie, decided to try to stop the annual howling forever.

Enter Agatha and her resourceful friend Ophelia, who join forces with the family to unravel the mystery behind Phoebe's relentless howling. Nothing like two older, knowledgeable women to help unravel a century-old mystery. Detective Destry enlists his team of sleuths from the police department, masking their true mission as a "cold case" investigation. But how cold must a case be for a restless spirit to find peace?

Zaryn, a brilliant CSI agent, takes the lead in deciphering Phoebe's torment. Unbeknownst to the sleuths, some folks in the 21st century are determined to keep the ghosts and secrets of the early 20th century buried. As Minerva's unconventional team, Detective Destry, Zaryn, and the rest delve deeper into the past, they unwittingly trigger danger, and Zaryn is the target.

A chilling race against time ensues as they confront the specters of history and face unforeseen peril. Who will emerge from this paranormal investigation unscathed, and can they finally quell Phoebe's restless soul?

Minerva and the Upstairs Ghost is a suspenseful tale where the line between the living and the dead blurs, and the answer to every question lies in the haunted echoes of the past.