“The Fifth Gospel” by Ian Caldwell

It is 2004. Father Alex Andreou is an Eastern Catholic priest – he follows Greek Orthodox theology and teaching (including allowing priests to marry) but is subservient to the Roman Catholic pope in Rome. Alex grew up in Vatican City and still lives in the apartment that had been assigned to his family. Living with him is his young son, Peter. Alex’s wife Mona abandoned the family some five years before – without explanation.

Alex’s brother Simon is also a priest – but chose to follow the Roman Catholic tradition. The brothers are close, and it is Alex to whom Simon turns one night, asking for help. Simon is at Castel Gandolfo, the summer residence of the popes 15 miles south of Rome. When Alex arrtives, he finds Simon with the body of Ugolina Nogara, the researcher who is assembling an exhibit at the Vatican due to open in a week’s time. Nogara has been shot in the head.

The exhibit is about the Diatessaron, a harmony of the four gospels written between 160 and 175 A.D. by Tatian, an early Christian writer and theologian. Both Alex and Simon have assisted Nogara with the preparation for it. What they also learn is that the exhibit is also about the Shroud of Turin, and how it came to be ledged in the cathedral there. In fact, unknown to almost everyone, the shroud is now within the confines of Vatican City. And only one person could have authorized the transfer from Turin – the ailing pope, John Paul II.

And then Simon is taken into custody to face a canonical or church trial for the murder of Nogara. If convicted, he will be stripped of his priesthood and turned over to civil authorities.

That’s the premise for The Fifth Gospel by Ian Caldwell. And it is a riveting story, which, except for the opening scene in Castel Gandolfo, takes place completely within the 110 acres of Vatican City in central Rome.

Caldwell weaves an absorbing tale of church history, Roman Catholic and Greek Orthodox relations, Vatican politics, the end of the John Paul II era, the relationship of two brothers, and a priest who dearly loves his son and still dearly loves his estranged wife. He mixes historical fact with fiction so well that the reader is never quite sure where one ends and the other begins.

Ian Caldwell

The research supporting the novel is striking. Caldwell was the co-author (with Duston Thomason) of the 2004 bestseller The Rule of Four, which sold more than two million copies. He worked on what became The Fifth Gospel for more than a decade until it was published in 2015.

To save the brother he dearly loves, Alex becomes a detective and uses his many connections within Vatican City to slowly ferret out the truth of what’s happened. And that’s the heart of the story and what drives it forward – the love within the family.

The Fifth Gospel is one terrific story.

Photograph: St. Peter’s Square in Vatican City.