On the Fifth Day — A.J. Hartley

The mysterious death of a Catholic priest has been met with suspicion by his brother, Thomas Knight--and the grave silence of church authorities. All Thomas knows is that his brother died in the Philippines, the last stop of an international trek researching the history of Christian symbols. But Thomas and curator Deborah Miller aren't alone in retracing the priest's perilous and labyrinthine path. Their every, move is being shadowed by a fanatical cabal of agents who are desperate to hide the astonishing secret Thomas's brother stumbled upon--and willing to kill to keep it buried in shadows of history forever.