Three nuns are murdered in the attic of a Boston convent. There are no witnesses. No shell casings. 

The only things missing are their rosaries.

Days later, a Boston medium claims her spirit guide has identified the killer: a broken priest with an antique revolver. A single newspaper column turns that claim into a city-wide witch hunt.

Harvard “pope whisperer” Cal Donovan and former Vatican power broker Elisabetta Celestino step into the city’s séance rooms to test the story.

What they uncover is a trail of antique ballistics, buried secrets, and a generations-old vendetta that reaches back to Arthur Conan Doyle and the birth of modern Spiritualism.

To save an innocent man, Cal and Elisabetta must decide whether they are chasing a brilliant fraud who hides behind the dead, or facing something far more unsettling: the dead really are answering back.

From international bestselling author Glenn Cooper, Covenant of the Dead is a standalone Cal Donovan thriller blending historical mystery, murder, and religious intrigue for readers of Dan Brown and Steve Berry.