The most important word in this entire book is the noun in the subtitle; this is a "novel"-a work of fiction. That is important to remember, especially after the statements on page 1, which move the work slightly into the arena of historical fiction, but only slightly. It is true that there are such organizations as the Priory of Sion and Opus Dei. It is true that the author has worked hard to describe accurately the contemporary European locations, including city layouts, buildings, and artwork, in which the plot is set. The statement that "all descriptions of... documents... in this novel are accurate" is, however, highly inaccurate!

The cross of Christ, as if it were the glittering eye of God, has in a most wondrous way held man spell-bound, and made him listen to its strange story "like a three years' child" who "cannot choose but hear." Were not the fact so familiar, men would call it miraculous. Had its action and history been capable of a priori statement, it would have seemed, even to the most credulous age, the maddest of mad and unsubstantial dreams. For it is not only that in the immense history of human experience it stands alone, a fact without a fellow, the most potent factor of human good, yet with what seems the least inherent fitness for it, but it even appears to contradict the most certain and common principles man has deduced from his experience. We do not wonder at the cross having been a stumbling-block to the Jew and foolishness to the Greek. We should have wondered much more had it been anything else.

The meaning ordinarily attached to the word "cross" is that of a figure composed of two or more lines which intersect, or touch each other transversely. Thus, two pieces of wood, or other material, so placed in juxtaposition to one another, are understood to form a cross. It should be noted, however, that Lipsius and other writers speak of the single upright stake to which criminals were bound as a cross, and to such a stake the name of crux simplex has been applied. The usual conception, however, of a cross is that of a compound figure. Punishment by crucifixion was widely employed in ancient times. It is known to have been used by nations such as those of Assyria, Egypt, Persia, by the Greeks, Carthaginians, Macedonians, and from very early times by the Romans. It has been thought, too, that crucifixion was also used by the Jews themselves, and that there is an allusion to it (Deut. xxi. 22, 23) as a punishment to be inflicted.