She saw Shorty standing among them--she recognized them as Circle L cowboys.

Shorty's guns were out; in fact the men in the group near Shorty seemed to bristle with weapons.
At the rear of the room was another group of men.

They stood motionless, silent, and had no weapons in their hands.

But some of them were crouching, their faces grim and set.
And then Ruth heard Shorty's voice--hoarse, raucous with passion: "You guys that don't belong to Slade's gang, get out! Fan it! You Slade men stand! I know every damned one of you!" There was a short silence, during which several men slipped away from the group at the rear of the room and bolted for the rear door.

And then, suddenly, as Shorty muttered words that Ruth did not hear, both groups of men leaped into action.
Ruth saw the men in the group at the rear reach, concertedly, for their weapons; she saw smoke streaks stabbing the heavy atmosphere of the big room; heard the roar and crash of pistols; saw men falling, to land in grotesque positions; saw Shorty, huge and terrible amid the billowing smoke, shoot a man who tried to leap over the bar, so that he fell across it limply, as though sleeping.