For more detailed information on James Becker (one of the many noms de plume of author Peter Stuart Smith) see my discussion of the first book in this series, The First Apostle. In 2013 Becker published what seemed to be the last adventure with Charles Bronson and his ex-wife Angela Lewis before turning to his Templar series featuring another code-busting couple. (In 2017, Becker published another Bronson-Lewis adventure, confusingly called The Templar Heresy). All of the novels find Bronson, a highly resourceful London police officer, and Lewis, a bewilderingly polymathic British Museum curator, falling into the search for various lost, stolen, and dangerous antiquities.
Three of the novels deal with early Christianity: The First Apostle revealed that Peter and Paul deliberately pacified Jesus' revolutionary movement as agents of Nero; The Messiah Secret revealed that the miraculous healer Jesus survived the crucifixion and ended up in northern India where his tomb and redheaded descendants could be found; and The Lost Testament deals with Jesus' conception by Mary and the gospel accounts of the Virgin Birth.
The documents at question in The Lost Testament had been discovered by the Emperor Constantine in the fourth century, remained hidden in the Vatican until accidentally stolen in the 1960s, and reappeared in the time of the novel on the Middle East antiquities market. Multiple Vatican conspiracy threads appear in this novel: the mysterious death of short-lived Pope John Paul I (see also The Pope's Assassin); the Vatican banking scandal of the 1980s (see also Gospel Truths); and the Vatican criminal syndicate Propaganda Due (who will also appear in Secret of the Templars).
Intertwined with these Vatican conspiracies are ancient rumors about Jesus being the illegitimate child of Mary and a Roman soldier named Pantera. The story appears already in the second-century Roman writer Celsus's anti-Christian treatise The True Logos and is taken up with vigor by the medieval Jewish compilation Toledot Yeshu. Interestingly, Becker's plot in The First Apostle also has resonances with the Toledot Yeshu, although neither book refers to it.
The name Pantera or Panthera was long thought to be an invention, perhaps a (deliberate) confusion of parthenos ("virgin" in Greek). James Tabor, in his book The Jesus Dynasty, connected the stories with the tombstone of a Roman named Tiberius Julius Abdes Pantera, discovered in Germany in the 19th century. The inscription suggests that Pantera was from the Near East ("Abdes" is almost certainly an Aramaic or Hebrew name); Tabor speculated that there might be truth to this very early story.
Becker takes up Tabor's claim and posits a trial record of Mary's rape; at the end of the novel, however, the status of this document is left unsettled: whether it is a real trial record or an ancient forgery is left up in the air.
Like The First Apostle, The Lost Testament also introduces the profits and perils of the interconnected webs of cyberspace: here, Becker posits a Vatican-constructed internet monitor called "Codex-S" which monitors searches and alerts the secret Vatican conspirators whenever certain search terms are strung together. By the twenty-first century, "the Internet" has taken on many of the fears and desires U.S. culture had long associated with "the Bible": a source of knowledge that is also possibly treacherous.
I could find no print reviews of The Lost Testament and it seems to have gone unnoticed by Publishers Weekly or Kirkus Reviews. By this time Becker had published several well-read novels, and had even embarked on some since-abandoned attempts at social media (a Twitter account, a webpage).
A single blog review calls it: "a thrilling pageturner."
Goodreads readers had very mixed response: from gushing praise to total despair. Amazon readers were slightly more enthusiastic.