Harry Freedman
O Books, £11.99

At the Limmud conference a couple of years ago, one of the bestselling books was an introduction to the New Testament written by a rabbi. It indicated the growing trend of Jewish curiosity about the origins of Christianity, whose sacred texts would once have simply been shunned as antisemitic heresy.

The Gospels' Veiled Agenda is an addition, by the former director of the Assembly of Masorti Synagogues, to the expanding literature on Jesus the Jew. But what will prick popular interest in particular is that it offers a Jewish explanation to an enduring legend, that of the Holy Grail.

Freedman presents Jesus not as the Messiah of Christian lore but as a religious revolutionary who wanted to replace the clerical establishment of his day - a corrupt priesthood propped up through collaboration with the Roman occupiers of ancient Israel.

The priests already faced opposition from the Pharisees, the rabbis who provided alternative leadership through intellectual meritocracy based on knowledge of Torah.

Freedman argues that Jesus chose a different path: he sought to instal a new body of priests worthier to be the spiritual leaders of the Jewish people. This posed a threat not only to the existing priesthood but to the Romans who would be suspicious of a more independently-minded Jewish leadership in the Temple, the centre of national feeling.

The holder of a doctorate in Aramaic translation of the Torah, Freedman deploys his knowledge of midrash with ingenuity, using the techniques of rabbinic interpretation to connect Hebrew sources with material in the Gospels. While his speculations rest on scholarship, he wears it lightly, leading the reader in an easy style to his conclusions about the Grail.

As for that elusive artefact, I am not going to pre-empt anyone's pleasure by revealing the detail of his theory. Only to say that he believes it not to be a chalice but a different kind of sacred object linked to priestly ceremony and critical to Jesus's aspirations.