Vatican whodunit: What ever happened to the books on marriage that were mailed to bishops?

A whodunit is making the rounds at the Vatican.

The publisher of a book on traditional Catholic marriage is crying foul, saying someone apparently swiped as many as 100 copies of the book from the Vatican mailboxes of bishops who attended a controversial meeting on family issues last October.

The publisher sent the books to attendees to counter progressive proposals by Pope Francis' favorite theologian to let divorced and civilly remarried Catholics receive Communion.

The book, penned by five high-ranking, conservative cardinals, explains that the suggestion is simply contrary to Christ's teaching on the indissolubility of marriage.

The Vatican spokesman insists the books were delivered without impediment.

But the mystery remains: What happened to the books?