There is an inviolate ritual attached to the pistol.

The actor about to get shot was taken backstage before the scene, as he is every time, and shown the gun and the ammunition — a handful of blanks. He was also shown that the gun had been altered so it could not use real bullets — information that enabled him to go on without fearing that he might be the unwitting victim of a sudden Agatha Christie-style theatrical murder.

There was a second gun backstage, ready to be fired if for some reason the gun onstage failed to go off (so far, that hasn’t happened). And after the climactic scene and then the curtain, Mr. Zajac was, as always, waiting in the wings, stage left.

“After the first bow, I receive the gun from Paddy,” he said, referring to Paddy Considine, the actor who plays the key role of Quinn Carney. “And then I unload it, put it in its case, and put it back into the gun safe.”

And then cleanup begins.