The Abbot's exhortation was an attempt to control the upcoming commotion: the people of Naples have witnessed in its history that when the miracle doesn't happen, it's often a premonition of evil. Some of the occasions where the blood didn't liquefy in the last few decades were: 1980, when a terrible earthquake hit South Italy; 1973, when Naples suffered an outbreak of cholera; 1939, when World War II broke out; 1940, when Italy joined the War; 1943, when Italy was occupied by the Nazis. And throughout the centuries the absence of the astonishing phenomenon has been precedent to religious persecutions, eruptions of the Mount Vesuvius, earthquakes, revolutions, wars and the deaths of kings, archbishops and Popes. Rarely the liquefaction happens outside of the three traditional dates.
That darn blood.