What to do at Mass in case of gunfire

Cute: Fr. Z, "What rubrics to follow at Mass in case of gunfire?" (WDTPRS, December 9, 2009):

From a reader:

I have a question for you. Suppose during a EF Mass, a gunman or threatening person enters the church, and opens fire. What can be done within the rubrics to protect the Blessed Sacrament, the priest, the servers, and the congregation? Please keep in mind that the congregation is made up of slow, aging men, who no offense to them, really can’t protect anyone.

Lemme get this straight ... what rubrics are followed in case of gunfire...?

I believe there is a little known rubric which calls for the deacon and subdeacon (who in any event should be packing) to take out, reverently, their .9mm and return fire. As I read it, they are to recite the Maledictory Psalms while firing. At the change of a clip/magazine, they may bow, or duck.

... Alternately, if the sacred ministers are not packing, there is no reason why a group of religious could not be formed as a sort of liturgical militia against such an eventuality. I believe in this case, the gun stock must have a ribbon of the color of the days....

Seriously ...

[Hat tip to M.L.]