The Magdalene Cipher: Jim Hougan

After someone he had under surveillance is slaughtered, CIA agent Jack Dunphy is order to leave London and return to the US where he's dumped in a tedious desk job that seems calculated to make him quit. Determined to discover why, Jack uses his tradecraft on the agency - and discovers fragments of a story that seems too wild to be true - a conspiracy reaching back to the time of Christ, a conspiracy so vast and deep the CIA itself is but a cover for it.