Triskaidekaphobia

On Friday, 13 October 1307, hundreds of the Knights Templar were arrested in France, an action apparently motivated financially and undertaken by the efficient royal bureaucracy to increase the prestige of the crown. King Philip IV was the force behind this ruthless move, but it has also tarnished the historical reputation of Pope Clement V. From the very day of Clement V's coronation, the King falsely charged the Templars with heresy, immorality, and abuses, and the scruples of the Pope were compromised by a growing sense that the burgeoning French State might not wait for the Church, but would proceed independently.
The connection between the Friday the 13th superstition and the Knights Templar was popularized in Dan Brown's 2003 novel The Da Vinci Code and in John J. Robinson's 1989 work Born in Blood: The Lost Secrets of Freemasonry.

Rico says he wonders why, whenever he sees their slogan In Hoc Signo Vinces ('In this sign I conquer'), he always thinks of Señor Wences...